Time Frames of Spoken Language Steven Greenberg International Computer Science Institute 1947 Center Street, Berkeley, CA In Collaboration with Hannah Carvey, Leah Hitchcock and Shawn Chang

Acknowledgements and Thanks Statistical Analysis and Automatic Classification Hannah Carvey, Shawn Chang, Leah Hitchcock Research Funding U.S. National Science Foundation U.S. Department of Defense

For Further Information Consult the web site:

OVERTURE The Central Challenge for Models of Speech Recognition

Language - The Traditional Perspective The “classical” view of spoken language posits a quasi-arbitrary relation between the lower and higher tiers of linguistic organization Cat= [k] + [ae] + [t] Cat = /k/ + /ae/ + /t/

The Serial Frame Perspective on Speech Traditional models of speech recognition assume the identity of a phonetic segment is derived from a detailed spectral profile of the acoustic signal (provided courtesy of the auditory system) computed for each interval (frame) of speech

The Serial Frame Perspective on Speech Traditional models of speech recognition assume the identity of a phonetic segment is derived from a detailed spectral profile of the acoustic signal (provided courtesy of the auditory system) computed for each interval (frame) of speech (this is literally how automatic speech recognition systems decode the speech signal)

Challenge Number One Pronunciation Variability

Pronunciation Variability of Real Speech Pronunciation patterns encountered in everyday life are extremely diverse

Pronunciation Variability of Real Speech Pronunciation patterns encountered in everyday life are extremely diverse The are literally dozens of ways in which common words are pronounced

Pronunciation Variability of Real Speech Pronunciation patterns encountered in everyday life are extremely diverse The are literally dozens of ways in which common words are pronounced (as the following two slides illustrate for the word “and” based on manual phonetic annotation of a corpus comprising telephone dialogues)

How Many Pronunciations of “and”? NPronunciationN Canonical pronunciation

How Many Pronunciations of “and”? NPronunciationN

Pronunciation Variability of Real Speech The are literally dozens of ways in which common words are pronounced And as the following slide illustrates for the 20 most frequent words from the same corpus (Switchboard)

How Many Different Pronunciations? RankWordN#Pron Most Common Pronunciation MCP %Total The 20 most frequent words account for 35% of the tokens

QUESTION How do listeners decode the speech signal given the large amount of pronunciation variation?

Challenge Number Two Acoustic Variability

Effects of Reverberation on the Speech Signal Reflections from walls and other surfaces routinely modify the spectro- temporal structure of the speech signal under everyday conditions

Effects of Reverberation on the Speech Signal Reflections from walls and other surfaces routinely modify the spectro- temporal structure of the speech signal under everyday conditions Yet, the intelligibility of speech is remarkably stable (unless the amount of reverberation or background noise is truly extreme)

Effects of Reverberation on the Speech Signal Reflections from walls and other surfaces routinely modify the spectro- temporal structure of the speech signal under everyday conditions Yet, the intelligibility of speech is remarkably stable (unless the amount of reverberation or background noise is truly extreme) How can this be so?

QUESTION Is there some acoustic property that provides a basis for perceptual stability of the speech signal?

An Invariant Property of the Speech Signal? Low-frequency energy fluctuations of the pressure waveform are largely preserved under many acoustic-interference conditions [based on an illustration by Hynek Hermansky] Modulation Spectrum

An Invariant Property of the Speech Signal? Low-frequency energy fluctuations of the pressure waveform are largely preserved under many acoustic-interference conditions In reverberant environments the MODULATION SPECTRUM’S peak is attenuated and shifted down to ca. 2 Hz (but is largely preserved) [based on an illustration by Hynek Hermansky] Modulation Spectrum

An Invariant Property of the Speech Signal? Low-frequency energy fluctuations of the pressure waveform are largely preserved under many acoustic-interference conditions In reverberant environments the modulation spectrum’s peak is attenuated and shifted down to ca. 2 Hz (but is largely preserved) (“What is the modulation spectrum?” you ask) [based on an illustration by Hynek Hermansky] Modulation Spectrum

An Invariant Property of the Speech Signal? Low-frequency energy fluctuations of the pressure waveform are largely preserved under many acoustic-interference conditions In reverberant environments the modulation spectrum’s peak is attenuated and shifted down to ca. 2 Hz (but is largely preserved) (“What is the modulation spectrum?” you ask) – Let’s find out! [based on an illustration by Hynek Hermansky] Modulation Spectrum

Modulation Spectrum Computation

Intelligibility and the Modulation Spectrum Significant attenuation (or distortion) of the modulation spectrum results in an appreciable decline in the ability to understand spoken language Greenberg and Arai (1998)

Intelligibility and the Modulation Spectrum Significant attenuation (or distortion) of the modulation spectrum results in an appreciable decline in the ability to understand spoken language Why should this be so? Greenberg and Arai (1998)

Anatomy of the Modulation Spectrum Why is the modulation spectrum’s integrity so crucial for intelligibility?

Anatomy of the Modulation Spectrum Why is the modulation spectrum’s integrity so crucial for intelligibility? What does it reflect linguistically?

Anatomy of the Modulation Spectrum Why is the modulation spectrum’s integrity so crucial for intelligibility? What does it reflect linguistically? Why is the bandwidth of the modulation spectrum associated with (intelligible) speech so broad?

Anatomy of the Modulation Spectrum Why is the modulation spectrum’s integrity so crucial for intelligibility? What does it reflect linguistically? Why is the bandwidth of the modulation spectrum associated with (intelligible) speech so broad? Modulation spectrum of 40 TIMIT sentences (computed across a 6-kHz bandwidth)

Anatomy of the Modulation Spectrum Why is the modulation spectrum’s integrity so crucial for intelligibility? What does it reflect linguistically? Why is the bandwidth of the modulation spectrum associated with (intelligible) speech so broad? Does the modulation spectrum reflect a unitary property of the speech signal? Modulation spectrum of 40 TIMIT sentences (computed across a 6-kHz bandwidth)

Anatomy of the Modulation Spectrum Why is the modulation spectrum’s integrity so crucial for intelligibility? What does it reflect linguistically? Why is the bandwidth of the modulation spectrum associated with (intelligible) speech so broad? Does the modulation spectrum reflect a unitary property of the speech signal? Or something more complex? Modulation spectrum of 40 TIMIT sentences (computed across a 6-kHz bandwidth)

The Modulation Spectrum Reflects Syllables The peak in the modulation spectrum (for speech) is ca. 5 Hz (200 ms)

The Modulation Spectrum Reflects Syllables The peak in the modulation spectrum (for speech) is ca. 5 Hz (200 ms) The distribution associated with SYLLABLE DURATION is similar to the pattern of the MODULATION SPECTRUM ….

The Modulation Spectrum Reflects Syllables The peak in the modulation spectrum (for speech) is ca. 5 Hz (200 ms) The distribution associated with SYLLABLE DURATION is similar to the pattern of the MODULATION SPECTRUM …. Syllable duration (in terms of equivalent Modulation frequency) Modulation Spectrum Modulation spectrum of a short excerpt from the Switchboard Corpus Syllable duration distribution associated with a 30-minute subset of Switchboard

The Modulation Spectrum Reflects Syllables The peak in the modulation spectrum (for speech) is ca. 5 Hz (200 ms) The distribution associated with SYLLABLE DURATION is similar to the pattern of the MODULATION SPECTRUM …. Suggesting that the latter reflects SYLLABLES Syllable duration (in terms of equivalent Modulation frequency) Modulation spectrum of a short excerpt from the Switchboard Corpus Syllable duration distribution associated with a 30-minute subset of Switchboard

The Trouble with Syllables … The question thus arises …

The Trouble with Syllables … The question thus arises … If the modulation spectrum truly reflects syllables in the speech signal

The Trouble with Syllables … The question thus arises … If the modulation spectrum truly reflects syllables in the speech signal Why is the distribution of syllable duration so broad?

The Trouble with Syllables … The question thus arises … If the modulation spectrum truly reflects syllables in the speech signal Why is the distribution of syllable duration so broad? Modulation spectrum of 15 minutes of spontaneous Japanese speech (OGI-TS corpus) compared with the syllable duration distribution for the same material (Arai and Greenberg, 1997) Syllable duration (modulation frequency) Modulation Spectrum

The Trouble with Syllables … The question thus arises … If the modulation spectrum truly reflects syllables in the speech signal Why is the distribution of syllable duration so broad? And does this variability in syllable duration reflect something significant? Syllable duration (modulation frequency) Modulation Spectrum Modulation spectrum of 15 minutes of spontaneous Japanese speech (OGI-TS corpus) compared with the syllable duration distribution for the same material (Arai and Greenberg, 1997)

PART ONE What Underlies Variation in Word Duration?

Word Duration Most words (81%) in the Switchboard corpus are monosyllabic, and most of the remainder are disyllabic (together comprising 95% of the words)

Word Duration Most words (81%) in the Switchboard corpus are monosyllabic, and most of the remainder are disyllabic (together comprising 95% of the words) The distribution of word duration therefore largely parallels that of syllables(plotted in units of duration [ms] on a logarithmic scale) All Words

What Underlies Word Duration Variability? Is this distribution of lexical duration of a uniform nature (and source)?

What Underlies Word Duration Variability? Is this distribution of lexical duration of a uniform nature (and source)? Or does it reflect a more complex set of phenomena?

What Underlies Word Duration Variability? Is this distribution of lexical duration of a uniform nature (and source)? Or does it reflect a more complex set of phenomena? It has been observed for WRITTEN text that the more frequent words tend to be shorter and the less common words longer (i.e., Zipf’s law)

What Underlies Word Duration Variability? Is this distribution of lexical duration of a uniform nature (and source)? Or does it reflect a more complex set of phenomena? It has been observed for WRITTEN text that the more frequent words tend to be shorter and the less common words longer (i.e., Zipf’s law) Does such a relationship hold for spoken language?

What Underlies Word Duration Variability? Is this distribution of lexical duration of a uniform nature (and source)? Or does it reflect a more complex set of phenomena? It has been observed for WRITTEN text that the more frequent words tend to be shorter and the less common words longer (i.e., Zipf’s law) Does such a relationship hold for spoken language? Let’s find out!

Is Word Duration Related to Word Frequency? Word duration (derived from the phonetically annotated portion of the Switchboard corpus) can be plotted relative to frequency of occurrence

Is Word Duration Related to Word Frequency? Word duration (derived from the phonetically annotated portion of the Switchboard corpus) can be plotted relative to frequency of occurrence r = – 0.42 Words with fewer than 5 instances omitted from graph

Is Word Duration Related to Word Frequency? Word duration (derived from the phonetically annotated portion of the Switchboard corpus) can be plotted relative to frequency of occurrence Such an exercise shows that there is a WEAK relationship (r = – 0.42) between lexical (unigram) frequency and word duration r = – 0.42 Words with fewer than 5 instances omitted from graph

Is Word Duration Related to Word Frequency? Word duration (derived from the phonetically annotated portion of the Switchboard corpus) can be plotted relative to frequency of occurrence Such an exercise shows that there is a WEAK relationship (r = – 0.42) between lexical (unigram) frequency and word duration There is a lot of variability in word duration for any given frequency range r = – 0.42 Words with fewer than 5 instances omitted from graph

Is Word Duration Related to Word Frequency? Word duration (derived from the phonetically annotated portion of the Switchboard corpus) can be plotted relative to frequency of occurrence Such an exercise shows that there is a WEAK relationship (r = – 0.42) between lexical (unigram) frequency and word duration There is a lot of variability in word duration for any given frequency range Suggesting that lexical frequency, alone, is unlikely to account for variation in word duration r = – 0.42 Words with fewer than 5 instances omitted from graph

If Not (entirely) Word Frequency, Then What? One parameter that might be more directly related to word duration (and other durational properties of speech) is STRESS ACCENT

If Not (entirely) Word Frequency, Then What? One parameter that might be more directly related to word duration (and other durational properties of speech) is STRESS ACCENT Stress Accent is related to the emphasis (or prominence) associated with individual syllables within a word

If Not (entirely) Word Frequency, Then What? One parameter that might be more directly related to word duration (and other durational properties of speech) is STRESS ACCENT Stress Accent is related to the emphasis (or prominence) associated with individual syllables within a word Although dictionaries list the stress patterns associated with words, this information is but a rough guide to the actual patterns observed (as is the phonetic pronunciation provided in the dictionary)

If Not (entirely) Word Frequency, Then What? One parameter that might be more directly related to word duration (and other durational properties of speech) is STRESS ACCENT Stress Accent is related to the emphasis (or prominence) associated with individual syllables within a word Although dictionaries list the stress patterns associated with words, this information is but a rough guide to the actual patterns observed (as is the phonetic pronunciation provided in the dictionary) In order to obtain empirical data pertaining to stress accent, it is necessary to manually annotate a corpus (syllable by syllable)

If Not (entirely) Word Frequency, Then What? One parameter that might be more directly related to word duration (and other durational properties of speech) is STRESS ACCENT Stress Accent is related to the emphasis (or prominence) associated with individual syllables within a word Although dictionaries list the stress patterns associated with words, this information is but a rough guide to the actual patterns observed (as is the phonetic pronunciation provided in the dictionary) In order to obtain empirical data pertaining to stress accent, it is necessary to manually annotate a corpus (syllable by syllable) This manual annotation has been performed for a 45-minute subset of the Switchboard corpus, which has also been labeled with respect to phonetic segments, syllables and words

If Not (entirely) Word Frequency, Then What? One parameter that might be more directly related to word duration (and other durational properties of speech) is STRESS ACCENT Stress Accent is related to the emphasis (or prominence) associated with individual syllables within a word Although dictionaries list the stress patterns associated with words, this information is but a rough guide to the actual patterns observed (as is the phonetic pronunciation provided in the dictionary) In order to obtain empirical data pertaining to stress accent, it is necessary to manually annotate a corpus (syllable by syllable) This manual annotation has been performed for a 45-minute subset of the Switchboard corpus, which has also been labeled with respect to phonetic segments, syllables and words It is thus possible to ascertain the relationship between stress accent and duration at the level of the word, syllable and phonetic segment

If Not (entirely) Word Frequency, Then What? One parameter that might be more directly related to word duration (and other durational properties of speech) is STRESS ACCENT Stress Accent is related to the emphasis (or prominence) associated with individual syllables within a word Although dictionaries list the stress patterns associated with words, this information is but a rough guide to the actual patterns observed (as is the phonetic pronunciation provided in the dictionary) In order to obtain empirical data pertaining to stress accent, it is necessary to manually annotate a corpus (syllable by syllable) This manual annotation has been performed for a 45-minute subset of the Switchboard corpus, which has also been labeled with respect to phonetic segments, syllables and words It is thus possible to ascertain the relationship between stress accent and duration at the level of the word, syllable and phonetic segment The remainder of this presentation focuses on the statistical relationship between stress accent and duration at these different linguistic tiers

If Not (entirely) Word Frequency, Then What? One parameter that might be more directly related to word duration (and other durational properties of speech) is STRESS ACCENT Stress Accent is related to the emphasis (or prominence) associated with individual syllables within a word Although dictionaries list the stress patterns associated with words, this information is but a rough guide to the actual patterns observed (as is the phonetic pronunciation provided in the dictionary) In order to obtain empirical data pertaining to stress accent, it is necessary to manually annotate a corpus (syllable by syllable) This manual annotation has been performed for a 45-minute subset of the Switchboard corpus, which has also been labeled with respect to phonetic segments, syllables and words It is thus possible to ascertain the relationship between stress accent and duration at the level of the word, syllable and phonetic segment The remainder of this presentation focuses on the statistical relationship between stress accent and duration at these different linguistic tiers Before examining these data, let’s briefly consider the nature of the annotated material

If Not (entirely) Word Frequency, Then What? One parameter that might be more directly related to word duration (and other durational properties of speech) is STRESS ACCENT Stress Accent is related to the emphasis (or prominence) associated with individual syllables within a word Although dictionaries list the stress patterns associated with words, this information is but a rough guide to the actual patterns observed (as is the phonetic pronunciation provided in the dictionary) In order to obtain empirical data pertaining to stress accent, it is necessary to manually annotate a corpus (syllable by syllable) This manual annotation has been performed for a 45-minute subset of the Switchboard corpus, which has also been labeled with respect to phonetic segments, syllables and words It is thus possible to ascertain the relationship between stress accent and duration at the level of the word, syllable and phonetic segment The remainder of this presentation focuses on the statistical relationship between stress accent and duration at these different linguistic tiers Before examining these data, let’s briefly consider the nature of the annotated material (this is important for evaluating the reliability of the results obtained)

INTERMEZZO Being Phonetically (and Prosodically) Annotated

Phonetic Transcription of Spontaneous English Telephone Dialogues of 5-10 minutes duration, from the SWITCHBOARD corpus, have been phonetically annotated (labeled and segmented)

Phonetic Transcription of Spontaneous English Telephone Dialogues of 5-10 minutes duration, from the SWITCHBOARD corpus, have been phonetically annotated (labeled and segmented) Most of this Material has been Manually Annotated

Phonetic Transcription of Spontaneous English Telephone Dialogues of 5-10 minutes duration, from the SWITCHBOARD corpus, have been phonetically annotated (labeled and segmented) Most of this Material has been Manually Annotated 4 hours labeled at the phone level and segmented at the syllabic level

Phonetic Transcription of Spontaneous English Telephone Dialogues of 5-10 minutes duration, from the SWITCHBOARD corpus, have been phonetically annotated (labeled and segmented) Most of this Material has been Manually Annotated 4 hours labeled at the phone level and segmented at the syllabic level 1 hour labeled and segmented at the phonetic-segment level

Phonetic Transcription of Spontaneous English Telephone Dialogues of 5-10 minutes duration, from the SWITCHBOARD corpus, have been phonetically annotated (labeled and segmented) Most of this Material has been Manually Annotated 4 hours labeled at the phone level and segmented at the syllabic level 1 hour labeled and segmented at the phonetic-segment level The remaining material has been segmented at the phonetic-segment level using automatic methods

Phonetic Transcription of Spontaneous English Telephone Dialogues of 5-10 minutes duration, from the SWITCHBOARD corpus, have been phonetically annotated (labeled and segmented) Most of this Material has been Manually Annotated 4 hours labeled at the phone level and segmented at the syllabic level 1 hour labeled and segmented at the phonetic-segment level The remaining material has been segmented at the phonetic-segment level using automatic methods 45 minutes of stress-accent-labeled material

Phonetic Transcription of Spontaneous English Telephone Dialogues of 5-10 minutes duration, from the SWITCHBOARD corpus, have been phonetically annotated (labeled and segmented) Most of this Material has been Manually Annotated 4 hours labeled at the phone level and segmented at the syllabic level 1 hour labeled and segmented at the phonetic-segment level The remaining material has been segmented at the phonetic-segment level using automatic methods 45 minutes of stress-accent-labeled material An additional four hours of material automatically labeled with respect to accent (this latter material not used in the current analysis, but will be available soon)

Phonetic Transcription of Spontaneous English Telephone Dialogues of 5-10 minutes duration, from the SWITCHBOARD corpus, have been phonetically annotated (labeled and segmented) Most of this Material has been Manually Annotated 4 hours labeled at the phone level and segmented at the syllabic level 1 hour labeled and segmented at the phonetic-segment level The remaining material has been segmented at the phonetic-segment level using automatic methods 45 minutes of stress-accent-labeled material An additional four hours of material automatically labeled with respect to accent (this latter material not used in the current analysis, but will be available soon) There is a Lot of Diversity in the Material Transcribed

Phonetic Transcription of Spontaneous English Telephone Dialogues of 5-10 minutes duration, from the SWITCHBOARD corpus, have been phonetically annotated (labeled and segmented) Most of this Material has been Manually Annotated 4 hours labeled at the phone level and segmented at the syllabic level 1 hour labeled and segmented at the phonetic-segment level The remaining material has been segmented at the phonetic-segment level using automatic methods 45 minutes of stress-accent-labeled material An additional four hours of material automatically labeled with respect to accent (this latter material not used in the current analysis, but will be available soon) There is a Lot of Diversity in the Material Transcribed Spans speech of both genders (ca. 50/50%), reflecting a wide range of American dialectal variation, speaking rate and voice quality

Phonetic Transcription of Spontaneous English Telephone Dialogues of 5-10 minutes duration, from the SWITCHBOARD corpus, have been phonetically annotated (labeled and segmented) Most of this Material has been Manually Annotated 4 hours labeled at the phone level and segmented at the syllabic level 1 hour labeled and segmented at the phonetic-segment level The remaining material has been segmented at the phonetic-segment level using automatic methods 45 minutes of stress-accent-labeled material An additional four hours of material automatically labeled with respect to accent (this latter material not used in the current analysis, but will be available soon) There is a Lot of Diversity in the Material Transcribed Spans speech of both genders (ca. 50/50%), reflecting a wide range of American dialectal variation, speaking rate and voice quality Transcription System A variant of Arpabet (which was also used for transcription of the TIMIT corpus)

Phonetic Transcription of Spontaneous English The Data are Available at ….

Phonetic Transcription of Spontaneous English The Data are Available at ….

Phonetic Transcription How was the Labeling and Segmentation Performed?

Phonetic Transcription How was the Labeling and Segmentation Performed? VERY carefully …. by UC-Berkeley linguistics students

Phonetic Transcription How was the Labeling and Segmentation Performed? VERY carefully …. by UC-Berkeley linguistics students Using a display of the signal waveform

Phonetic Transcription How was the Labeling and Segmentation Performed? VERY carefully …. by UC-Berkeley linguistics students Using a display of the signal waveform, spectrogram

Phonetic Transcription How was the Labeling and Segmentation Performed? VERY carefully …. by UC-Berkeley linguistics students Using a display of the signal waveform, spectrogram, word transcription

Phonetic Transcription How was the Labeling and Segmentation Performed? VERY carefully …. by UC-Berkeley linguistics students Using a display of the signal waveform, spectrogram, word transcription and “forced alignments” (automatic estimates of phones and boundaries)

Phonetic Transcription How was the Labeling and Segmentation Performed? VERY carefully …. by UC-Berkeley linguistics students Using a display of the signal waveform, spectrogram, word transcription and “forced alignments” (automatic estimates of phones and boundaries) + audio

Phonetic Transcription How was the Labeling and Segmentation Performed? VERY carefully …. by UC-Berkeley linguistics students Using a display of the signal waveform, spectrogram, word transcription and “forced alignments” (automatic estimates of phones and boundaries) + audio (listening at multiple time scales - phone, word, utterance) on Sun workstations

Phonetic Transcription How was the Labeling and Segmentation Performed? VERY carefully …. by UC-Berkeley linguistics students Using a display of the signal waveform, spectrogram, word transcription and “forced alignments” (automatic estimates of phones and boundaries) + audio (listening at multiple time scales - phone, word, utterance) on Sun workstations Additionally, automatic segmentation and labeling of articulatory manner was used as a guide for phonetic labeling and segmentation in recent work

Annotation of Stress Accent Forty-five minutes of the phonetically annotated portion of the Switchboard corpus was manually labeled with respect to stress accent

Annotation of Stress Accent Forty-five minutes of the phonetically annotated portion of the Switchboard corpus was manually labeled with respect to stress accent Three levels of accent were distinguished:

Annotation of Stress Accent Forty-five minutes of the phonetically annotated portion of the Switchboard corpus was manually labeled with respect to stress accent Three levels of accent were distinguished: Heavy

Annotation of Stress Accent Forty-five minutes of the phonetically annotated portion of the Switchboard corpus was manually labeled with respect to stress accent Three levels of accent were distinguished: HeavyLight

Annotation of Stress Accent Forty-five minutes of the phonetically annotated portion of the Switchboard corpus was manually labeled with respect to stress accent Three levels of accent were distinguished: HeavyLightNone

Annotation of Stress Accent Forty-five minutes of the phonetically annotated portion of the Switchboard corpus was manually labeled with respect to stress accent Three levels of accent were distinguished: HeavyLightNone

Annotation of Stress Accent Forty-five minutes of the phonetically annotated portion of the Switchboard corpus was manually labeled with respect to stress accent Three levels of accent were distinguished: HeavyLightNone (In actuality, labelers assigned a “1” to a fully accented syllables, a “null” to completely unaccented syllables, and a “0.5” to all others)

Annotation of Stress Accent Forty-five minutes of the phonetically annotated portion of the Switchboard corpus was manually labeled with respect to stress accent Three levels of accent were distinguished: HeavyLightNone (In actuality, labelers assigned a “1” to a fully accented syllables, a “null” to completely unaccented syllables, and a “0.5” to all others) An example of the annotation (attached to the vocalic nucleus) is shown below (where the accent levels could not be derived from a dictionary)

Annotation of Stress Accent Forty-five minutes of the phonetically annotated portion of the Switchboard corpus was manually labeled with respect to stress accent Three levels of accent were distinguished: HeavyLightNone (In actuality, labelers assigned a “1” to a fully accented syllables, a “null” to completely unaccented syllables, and a “0.5” to all others) An example of the annotation (attached to the vocalic nucleus) is shown below (where the accent levels could not be derived from a dictionary) In this example most of the syllables are unaccented, with two labeled as lightly accented (0.5)

Annotation of Stress Accent Forty-five minutes of the phonetically annotated portion of the Switchboard corpus was manually labeled with respect to stress accent Three levels of accent were distinguished: HeavyLightNone (In actuality, labelers assigned a “1” to a fully accented syllables, a “null” to completely unaccented syllables, and a “0.5” to all others) An example of the annotation (attached to the vocalic nucleus) is shown below (where the accent levels could not be derived from a dictionary) In this example most of the syllables are unaccented, with two labeled as lightly accented (0.5) (and one other labeled as very lightly accented (0.25))

PART TWO The Relation between Stress Accent and Word Duration

Back to Stress Accent and Word Duration… Stress accent is supposed to bear some systematic relation to three principal acoustic parameters of the speech signal:

Back to Stress Accent and Word Duration… Stress accent is supposed to bear some systematic relation to three principal acoustic parameters of the speech signal: Fundamental Frequency

Back to Stress Accent and Word Duration… Stress accent is supposed to bear some systematic relation to three principal acoustic parameters of the speech signal: Fundamental FrequencyAmplitude

Back to Stress Accent and Word Duration… Stress accent is supposed to bear some systematic relation to three principal acoustic parameters of the speech signal: Fundamental FrequencyAmplitude Duration

Back to Stress Accent and Word Duration… Stress accent is supposed to bear some systematic relation to three principal acoustic parameters of the speech signal: Fundamental FrequencyAmplitude Duration

Back to Stress Accent and Word Duration… Stress accent is supposed to bear some systematic relation to three principal acoustic parameters of the speech signal: Fundamental FrequencyAmplitude Duration In previous studies my colleagues and I have shown that f 0 -related cues play a relatively small role in stress accent assignment (at least for spontaneous American English material)

Back to Stress Accent and Word Duration… Stress accent is supposed to bear some systematic relation to three principal acoustic parameters of the speech signal: Fundamental FrequencyAmplitude Duration In previous studies my colleagues and I have shown that f 0 -related cues play a relatively small role in stress accent assignment (at least for spontaneous American English material) Amplitude and duration appear to play a far more important role than f 0

Back to Stress Accent and Word Duration… Stress accent is supposed to bear some systematic relation to three principal acoustic parameters of the speech signal: Fundamental FrequencyAmplitude Duration In previous studies my colleagues and I have shown that f 0 -related cues play a relatively small role in stress accent assignment (at least for spontaneous American English material) Amplitude and duration appear to play a far more important role than f 0 Therefore, it is not unreasonable to assume that the stress accent patterns associated with words bear some tangible relation to lexical duration

Back to Stress Accent and Word Duration… Stress accent is supposed to bear some systematic relation to three principal acoustic parameters of the speech signal: Fundamental FrequencyAmplitude Duration In previous studies my colleagues and I have shown that f 0 -related cues play a relatively small role in stress accent assignment (at least for spontaneous American English material) Amplitude and duration appear to play a far more important role than f 0 Therefore, it is not unreasonable to assume that the stress accent patterns associated with words bear some tangible relation to lexical duration So …

Back to Stress Accent and Word Duration… Stress accent is supposed to bear some systematic relation to three principal acoustic parameters of the speech signal: Fundamental FrequencyAmplitude Duration In previous studies my colleagues and I have shown that f 0 -related cues play a relatively small role in stress accent assignment (at least for spontaneous American English material) Amplitude and duration appear to play a far more important role than f 0 Therefore, it is not unreasonable to assume that the stress accent patterns associated with words bear some tangible relation to lexical duration So …, let’s find out!

Word Duration and Stress Accent Level Let’s first examine the durational properties of heavily accented words

Word Duration and Stress Accent Level Let’s first examine the durational properties of heavily accented words (these are words containing at least one heavily accented syllable)

Word Duration and Stress Accent Level Let’s first examine the durational properties of heavily accented words (these are words containing at least one heavily accented syllable) The mean duration of this subset (36%) is 378 ms (s.d. = 168 ms) Heavily Accented

Word Duration and Stress Accent Level Let’s first examine the durational properties of heavily accented words (these are words containing at least one heavily accented syllable) The mean duration of this subset (36%) is 378 ms (s.d. = 168 ms) Most of the heavily accented words are longer than 200 ms Heavily Accented

Let’s now compare the duration of the heavily accented words with those of their lightly accented counterparts (25% of the total) Word Duration and Stress Accent Level Heavily Accented

Heavily Accented Lightly Accented Let’s now compare the duration of the heavily accented words with those of their lightly accented counterparts (25% of the total) The mean duration of this subset is 255 ms (s.d. = 116 ms) Word Duration and Stress Accent Level

Heavily Accented Lightly Accented Let’s now compare the duration of the heavily accented words with those of their lightly accented counterparts (25% of the total) The mean duration of this subset is 255 ms (s.d. = 116 ms) In many respects the durational properties of these two subsets are similar Word Duration and Stress Accent Level

Heavily Accented Lightly Accented Let’s now compare the duration of unaccented words with that of their accented counterparts Word Duration and Stress Accent Level

Heavily Accented Lightly Accented Unaccented Let’s now compare the duration of unaccented words with that of their accented counterparts The mean duration of the unaccented subset (39%) is 149 ms (s.d. = 78 ms) Word Duration and Stress Accent Level

Heavily Accented Lightly Accented Unaccented Let’s now compare the duration of unaccented words with that of their accented counterparts The mean duration of the unaccented subset (39%) is 149 ms (s.d. = 78 ms) The unaccented words are generally shorter than 200 ms Word Duration and Stress Accent Level

Heavily Accented Lightly Accented Unaccented Let’s now compare the duration of unaccented words with that of their accented counterparts The mean duration of the unaccented subset (39%) is 149 ms (s.d. = 78 ms) The unaccented words are generally shorter than 200 ms and constitute a very different distributional form than their accented counterparts Word Duration and Stress Accent Level

Heavily Accented Lightly Accented Unaccented Let’s now compare the durational properties of ALL WORDS in the corpus with those pertaining to words of varying accent levels Word Duration and Stress Accent Level

Heavily Accented Lightly Accented Unaccented All Words Word Duration and Stress Accent Level Let’s now compare the durational properties of ALL WORDS in the corpus with those pertaining to words of varying accent levels When we do so,

Heavily Accented Lightly Accented Unaccented All Words Word Duration and Stress Accent Level Let’s now compare the durational properties of ALL WORDS in the corpus with those pertaining to words of varying accent levels When we do so, we notice that the left-hand branch of the lexical distribution largely reflects unaccented words,

Heavily Accented Lightly Accented Unaccented All Words Word Duration and Stress Accent Level Let’s now compare the durational properties of ALL WORDS in the corpus with those pertaining to words of varying accent levels When we do so, we notice that the left-hand branch of the lexical distribution largely reflects unaccented words, while the right-hand branch reflects mostly accented words (with the peak reflecting both)

Heavily Accented Lightly Accented Unaccented All Words Word Duration and Stress Accent Level Therefore, it appears that the broad distribution of word duration (and, in turn, syllable duration) largely reflects the co-existence of accented and unaccented words within spontaneous speech

Heavily Accented Lightly Accented Unaccented All Words Word Duration and Stress Accent Level Therefore, it appears that the broad distribution of word duration (and, in turn, syllable duration) largely reflects the co-existence of accented and unaccented words within spontaneous speech What are the implications of this insight?

Breadth of the Modulation Spectrum The broad bandwidth of the modulation spectrum, therefore, appears to reflect the heterogeneity in syllabic and lexical duration associated with variation in stress accent level

Breadth of the Modulation Spectrum The broad bandwidth of the modulation spectrum, therefore, appears to reflect the heterogeneity in syllabic and lexical duration associated with variation in stress accent level Modulation spectrum of 40 TIMIT sentences (computed across a 6-kHz bandwidth) Unaccented Heavily Accented All Accents (Convergnce)

Breadth of the Modulation Spectrum The broad bandwidth of the modulation spectrum, therefore, appears to reflect the heterogeneity in syllabic and lexical duration associated with variation in stress accent level Does this insight have implications for the lower tiers of spoken language? Modulation spectrum of 40 TIMIT sentences (computed across a 6-kHz bandwidth) Unaccented Heavily Accented All Accents (Convergnce)

Breadth of the Modulation Spectrum The broad bandwidth of the modulation spectrum, therefore, appears to reflect the heterogeneity in syllabic and lexical duration associated with variation in stress accent level Does this insight have implications for the lower tiers of spoken language? (e.g., the phonetic and phonological levels) Modulation spectrum of 40 TIMIT sentences (computed across a 6-kHz bandwidth) Unaccented Heavily Accented All Accents (Convergnce)

Breadth of the Modulation Spectrum The broad bandwidth of the modulation spectrum, therefore, appears to reflect the heterogeneity in syllabic and lexical duration associated with variation in stress accent level Does this insight have implications for the lower tiers of spoken language? (e.g., the phonetic and phonological levels) Let’s find out! Modulation spectrum of 40 TIMIT sentences (computed across a 6-kHz bandwidth) Unaccented Heavily Accented All Accents (Convergnce)

INTERMEZZO Anatomy of the Syllable

The Importance of the Syllable The analyses to follow are all linked, in some fashion, to syllable structure

The Importance of the Syllable The analyses to follow are all linked, in some fashion, to syllable structure In order to highlight patterns germane to variation in segmental duration it is necessary to partition the data in terms of syllable position

The Importance of the Syllable The analyses to follow are all linked, in some fashion, to syllable structure In order to highlight patterns germane to variation in segmental duration it is necessary to partition the data in terms of syllable position (as well as stress accent level)

The Importance of the Syllable The analyses to follow are all linked, in some fashion, to syllable structure In order to highlight patterns germane to variation in segmental duration it is necessary to partition the data in terms of syllable position (as well as stress accent level) As a consequence, we will examine the onsets, codas and nuclei of syllables separately in order to gain insight into the underlying patterns

The Importance of the Syllable The analyses to follow are all linked, in some fashion, to syllable structure In order to highlight patterns germane to variation in segmental duration it is necessary to partition the data in terms of syllable position (as well as stress accent level) As a consequence, we will examine the onsets, codas and nuclei of syllables separately in order to gain insight into the underlying patterns What is an onset?

The Importance of the Syllable The analyses to follow are all linked, in some fashion, to syllable structure In order to highlight patterns germane to variation in segmental duration it is necessary to partition the data in terms of syllable position (as well as stress accent level) As a consequence, we will examine the onsets, codas and nuclei of syllables separately in order to gain insight into the underlying patterns What is a onset? What is a nucleus?

The Importance of the Syllable The analyses to follow are all linked, in some fashion, to syllable structure In order to highlight patterns germane to variation in segmental duration it is necessary to partition the data in terms of syllable position (as well as stress accent level) As a consequence, we will examine the onsets, codas and nuclei of syllables separately in order to gain insight into the underlying patterns What is a onset? What is a nucleus? What is a coda?

The Importance of the Syllable The analyses to follow are all linked, in some fashion, to syllable structure In order to highlight patterns germane to variation in segmental duration it is necessary to partition the data in terms of syllable position (as well as stress accent level) As a consequence, we will examine the onsets, codas and nuclei of syllables separately in order to gain insight into the underlying patterns What is a nucleus? What is a coda? What is a coda? The following slides provide a brief (and gentle) introduction to syllable structure

Syllable and Phonetic Segment Illustrated Syllables generally consist of three constituents - ONSET, NUCLEUS, CODA “J” = JUNCTURE

Syllable and Phonetic Segment Illustrated Syllables generally consist of three constituents - ONSET, NUCLEUS, CODA Virtually all syllables contain a NUCLEUS, which is VOCALIC (by definition) “J” = JUNCTURE

Syllable and Phonetic Segment Illustrated Syllables generally consist of three constituents - ONSET, NUCLEUS, CODA Virtually all syllables contain a NUCLEUS, which is VOCALIC (by definition) Most (but not all) syllables also contain an ONSET (usually a CONSONANT) “J” = JUNCTURE

Syllable and Phonetic Segment Illustrated Syllables generally consist of three constituents - ONSET, NUCLEUS, CODA Virtually all syllables contain a NUCLEUS, which is VOCALIC (by definition) Most (but not all) syllables also contain an ONSET (usually a CONSONANT) Many syllables contain a CODA (also typically a CONSONANT) “J” = JUNCTURE

Syllable and Phonetic Segment Illustrated Syllables generally consist of three constituents - ONSET, NUCLEUS, CODA Virtually all syllables contain a NUCLEUS, which is VOCALIC (by definition) Most (but not all) syllables also contain an ONSET (usually a CONSONANT) Many syllables contain a CODA (also typically a CONSONANT) The most common syllable form in English is Onset + Nucleus + Coda (“Nine”) “J” = JUNCTURE

Syllable and Phonetic Segment Illustrated Syllables generally consist of three constituents - ONSET, NUCLEUS, CODA Virtually all syllables contain a NUCLEUS, which is VOCALIC (by definition) Most (but not all) syllables also contain an ONSET (usually a CONSONANT) Many syllables contain a CODA (also typically a CONSONANT) The most common syllable form in English is Onset + Nucleus + Coda (“Nine”) Followed in popularity by Onset + Nucleus (“Two”) “J” = JUNCTURE

PART THREE Stress Accent and Syllable Position

The Importance of Syllable Structure Before going into the details of durational variation at the segmental level we briefly examine some general patterns of pronunciation variation that are conditioned by syllable position and stress accent

The Importance of Syllable Structure Before going into the details of durational variation at the segmental level we briefly examine some general patterns of pronunciation variation that are conditioned by syllable position and stress accent These data serve to illustrate the sort of variation observed that is conditioned by position within the syllable

All Segments Pronunciation Variation – Syllable and Accent Deletions Insertions Substitutions Pronunciation variation is systematic at the level of the syllable CODA Territory ONSET Territory NUCLEUS Territory

All Segments Pronunciation Variation – Syllable and Accent Deletions Insertions Substitutions Pronunciation variation is systematic at the level of the syllable It’s also systematic when stress accent is taken into account CODA Territory ONSET Territory NUCLEUS Territory

Pronunciation Variation – Syllable and Accent Pronunciation variation is systematic at the level of the syllable It’s also systematic when stress accent is taken into account BOTH syllable structure and accent level are required for a full accounting All Segments Deletions Insertions Substitutions CODA Territory ONSET Territory NUCLEUS Territory

A Coarse Perspective on Pronunciation Variation (at the level of the syllable and stress accent)

Analysis of Durational Properties of Speech The following analyses are conditioned on stress accent level and (for the most part) syllable position

Analysis of Durational Properties of Speech The following analyses are conditioned on stress accent level and (for the most part) syllable position We will begin with analyses illustrating the patterns associated with three levels of stress accent (heavy, light and none) to show the graded nature of the durational properties pertaining to syllable and segment duration

Analysis of Durational Properties of Speech The following analyses are conditioned on stress accent level and (for the most part) syllable position We will begin with analyses illustrating the patterns associated with three levels of stress accent (heavy, light and none) to show the graded nature of the durational properties pertaining to syllable and segment duration However, for purposes of illustrative clarity, many of the slides will show only two levels of accent (heavy and none) in order to delineate the differences in duration associated with stress accent level

Analysis of Durational Properties of Speech The following analyses are conditioned on stress accent level and (for the most part) syllable position We will begin with analyses illustrating the patterns associated with three levels of stress accent (heavy, light and none) to show the graded nature of the durational properties pertaining to syllable and segment duration However, for purposes of illustrative clarity, many of the slides will show only two levels of accent (heavy and none) in order to delineate the differences in duration associated with stress accent level Under such conditions, the durational properties associated with light accent are generally intermediate between heavy accent and none

Syllable Duration - Across Syllable Forms There is a broad range of syllable structures observed in spoken English

Syllable Duration - Across Syllable Forms There is a broad range of syllable structures observed in spoken English Together, the V, VC, CV and CVC forms account for 85% of syllables

Syllable Duration - Across Syllable Forms There is a broad range of syllable structures observed in spoken English Together, the V, VC, CV and CVC forms account for 85% of syllables The CVCC and CCVC forms account for another 10%

Syllable Duration - Across Syllable Forms There is a broad range of syllable structures observed in spoken English Together, the V, VC, CV and CVC forms account for 85% of syllables The CVCC and CCVC forms account for another 10% Together, the CV and CVC forms cover ca. 60% of the syllables

Syllable Duration - Across Syllable Forms It is not surprising that syllable duration is largely a function of the number of segments within the syllable (as shown in the graph below) Canonical Syllable Forms V = Vowel C = Consonant

Syllable Duration - Across Syllable Forms It is not surprising that syllable duration is largely a function of the number of segments within the syllable (as shown in the graph below) Note the systematic lengthening of the syllable for each form as the accent level increases from none to light to heavy Canonical Syllable Forms V = Vowel C = Consonant

Syllable Duration - Across Syllable Forms It is not surprising that syllable duration is largely a function of the number of segments within the syllable (as shown in the graph below) Note the systematic lengthening of the syllable for each form as the accent level increases from none to light to heavy This pattern is representative of accent’s impact on duration Canonical Syllable Forms V = Vowel C = Consonant

Syllable Duration - Across Syllable Forms It is not surprising that syllable duration is largely a function of the number of segments within the syllable (as shown in the graph below) Note the systematic lengthening of the syllable for each form as the accent level increases from none to light to heavy This pattern is representative of accent’s impact on duration (as we’ll see) Canonical Syllable Forms V = Vowel C = Consonant

Syllable Duration - Accent Level/Syllable Form Canonical Syllable Forms This graph shows the same data as the previous slides, but from the perspective of only two accent levels (heavy and none) V = Vowel C = Consonant

Syllable Duration - Accent Level/Syllable Form Canonical Syllable Forms This graph shows the same data as the previous slides, but from the perspective of only two accent levels (heavy and none) The heavily accented syllables are generally % longer than their unaccented counterparts V = Vowel C = Consonant

Syllable Duration - Accent Level/Syllable Form Canonical Syllable Forms This graph shows the same data as the previous slides, but from the perspective of only two accent levels (heavy and none) The heavily accented syllables are generally % longer than their unaccented counterparts The disparity in duration is most pronounced for syllable forms with one or no consonants (i.e., V, VC, CV) V = Vowel C = Consonant

Syllable Duration - Accent Level/Syllable Form Canonical Syllable Forms This graph shows the same data as the previous slides, but from the perspective of only two accent levels (heavy and none) The heavily accented syllables are generally % longer than their unaccented counterparts The disparity in duration is most pronounced for syllable forms with one or no consonants (i.e., V, VC, CV) This pattern implies that accent has the greatest impact on vocalic duration V = Vowel C = Consonant

Canonical Syllable Forms Nucleus Duration - Accent Level/Syllable Form The hypothesis delineated on the previous slide (that accent has the most profound impact on vocalic duration) is confirmed in the graph below

Canonical Syllable Forms Nucleus Duration - Accent Level/Syllable Form The hypothesis delineated on the previous slide (that accent has the most profound impact on vocalic duration) is confirmed in the graph below The duration of vowels in accented syllables (of all forms) are at least twice as long as their unaccented counterparts

Canonical Syllable Forms Nucleus Duration - Accent Level/Syllable Form The hypothesis delineated on the previous slide (that accent has the most profound impact on vocalic duration) is confirmed in the graph below The duration of vowels in accented syllables (of all forms) are at least twice as long as their unaccented counterparts This pattern implies that the syllable nucleus absorbs a major component of accent’s impact (at least as far as duration is concerned)

PART FOUR Stress Accent and the Vocalic Nucleus

Because the pattern of stress accent’s impact on vocalic duration is relatively uniform across syllable form it is likely that the structure of the syllable has relatively little impact on vocalic duration Stress Accent’s Impact on the Vocalic Nucleus

Because the pattern of stress accent’s impact on vocalic duration is relatively uniform across syllable form it is likely that the structure of the syllable has relatively little impact on vocalic duration As a consequence, the remaining analyses pertaining to accent’s impact on vocalic duration collapse the data across syllable form Stress Accent’s Impact on the Vocalic Nucleus

Because the pattern of stress accent’s impact on vocalic duration is relatively uniform across syllable form it is likely that the structure of the syllable has relatively little impact on vocalic duration As a consequence, the remaining analyses pertaining to accent’s impact on vocalic duration collapse the data across syllable form We now examine vocalic duration in somewhat greater detail and illustrate how duration, stress accent and vocalic identity interact Stress Accent’s Impact on the Vocalic Nucleus

Because the pattern of stress accent’s impact on vocalic duration is relatively uniform across syllable form it is likely that the structure of the syllable has relatively little impact on vocalic duration As a consequence, the remaining analyses pertaining to accent’s impact on vocalic duration collapse the data across syllable form We now examine vocalic duration in somewhat greater detail and illustrate how duration, stress accent and vocalic identity interact But first … a brief primer on vocalic acoustics Stress Accent’s Impact on the Vocalic Nucleus

Because the pattern of stress accent’s impact on vocalic duration is relatively uniform across syllable form it is likely that the structure of the syllable has relatively little impact on vocalic duration As a consequence, the remaining analyses pertaining to accent’s impact on vocalic duration collapse the data across syllable form We now examine vocalic duration in somewhat greater detail and illustrate how duration, stress accent and vocalic identity interact But first … a brief primer on vocalic acoustics (which should facilitate digesting the material that follows) Stress Accent’s Impact on the Vocalic Nucleus

INTERMEZZO A Brief Primer on Vowel Acoustics

A Brief Primer on Vocalic Acoustics

Vowel quality is generally thought to be a function primarily of two articulatory properties – both related to the motion of the tongue A Brief Primer on Vocalic Acoustics

Vowel quality is generally thought to be a function primarily of two articulatory properties – both related to the motion of the tongue The front-back plane is most closely associated with the second formant frequency (or more precisely F2 - F1) and the volume of the front-cavity resonance A Brief Primer on Vocalic Acoustics

Vowel quality is generally thought to be a function primarily of two articulatory properties – both related to the motion of the tongue The front-back plane is most closely associated with the second formant frequency (or more precisely F2 - F1) and the volume of the front-cavity resonance The height parameter is closely linked to the frequency of F1 A Brief Primer on Vocalic Acoustics

Vowel quality is generally thought to be a function primarily of two articulatory properties – both related to the motion of the tongue The front-back plane is most closely associated with the second formant frequency (or more precisely F2 - F1) and the volume of the front-cavity resonance The height parameter is closely linked to the frequency of F1 In the classic vowel “triangle,” segments are positioned in terms of the tongue positions associated with their production, as follows: A Brief Primer on Vocalic Acoustics

Vowel quality is generally thought to be a function primarily of two articulatory properties – both related to the motion of the tongue The front-back plane is most closely associated with the second formant frequency (or more precisely F2 - F1) and the volume of the front-cavity resonance The height parameter is closely linked to the frequency of F1 In the classic vowel “triangle,” segments are positioned in terms of the tongue positions associated with their production, as follows: A Brief Primer on Vocalic Acoustics

The Spatial Patterning of Duration in Vocalic Nuclei

Let’s return to the vowel triangle and see if it can shed light on certain patterns in the vocalic data Spatial Patterning of Duration

Let’s return to the vowel triangle and see if it can shed light on certain patterns in the vocalic data The duration will be plotted on a 2-D grid, where the x-axis will always be in terms of hypothetical front-back tongue position Spatial Patterning of Duration

Let’s return to the vowel triangle and see if it can shed light on certain patterns in the vocalic data The duration will be plotted on a 2-D grid, where the x-axis will always be in terms of hypothetical front-back tongue position (and hence remain a constant throughout the plots to follow) Spatial Patterning of Duration

Let’s return to the vowel triangle and see if it can shed light on certain patterns in the vocalic data The duration will be plotted on a 2-D grid, where the x-axis will always be in terms of hypothetical front-back tongue position (and hence remain a constant throughout the plots to follow) The y-axis will serve as the dependent measure expressed in terms of duration or the proportion of fully stressed (or unstressed) nuclei Spatial Patterning of Duration

Let’s return to the vowel triangle and see if it can shed light on certain patterns in the vocalic data The duration will be plotted on a 2-D grid, where the x-axis will always be in terms of hypothetical front-back tongue position (and hence remain a constant throughout the plots to follow) The y-axis will serve as the dependent measure expressed in terms of duration or the proportion of fully stressed (or unstressed) nuclei Spatial Patterning of Duration

Vocalic Duration and Vowel Height The spatial patterning of vocalic segments is systematic with respect to duration

Vocalic Duration and Vowel Height The spatial patterning of vocalic segments is systematic with respect to duration Low vowels, be they diphthongs or monophthongs, are longer (on average) than high vowels

Vocalic Duration and Vowel Height All nuclei DiphthongsMonophthongs The spatial patterning of vocalic segments is systematic with respect to duration Low vowels, be they diphthongs or monophthongs, are longer (on average) than high vowels

Vocalic Duration and Vowel Height All nuclei DiphthongsMonophthongs The spatial patterning of vocalic segments is systematic with respect to duration Low vowels, be they diphthongs or monophthongs, are longer (on average) than high vowels Thus, duration appears to be highly correlated with vowel height

Vocalic Duration and Vowel Height All nuclei DiphthongsMonophthongs The spatial patterning of vocalic segments is systematic with respect to duration Low vowels, be they diphthongs or monophthongs, are longer (on average) than high vowels Thus, duration appears to be highly correlated with vowel height But … the situation is a little more complicated than first appearances would suggest

Durational Differences - Stressed/Unstressed There is a large dynamic range in duration between accented and unaccented vocalic nuclei Canonical Syllable Forms

Durational Differences - Stressed/Unstressed There is a large dynamic range in duration between accented and unaccented vocalic nuclei Moreover, diphthongs and tense, low monophthongs tend to exhibit a larger dynamic range than the lax monophthongs Canonical Syllable Forms

Durational Differences - Stressed/Unstressed There is a large dynamic range in duration between accented and unaccented vocalic nuclei Moreover, diphthongs and tense, low monophthongs tend to exhibit a larger dynamic range than the lax monophthongs Canonical Syllable Forms Lax monophthongs

Vocalic Identity Among Unstressed Nuclei The high, lax monophthongs are almost always unstressed

Vocalic Identity Among Unstressed Nuclei The high, lax monophthongs are almost always unstressed The low vowels, be they monophthongs or diphthongs, are rarely unstressed

Vocalic Identity Among Unstressed Nuclei The high, lax monophthongs are almost always unstressed The low vowels, be they monophthongs or diphthongs, are rarely unstressed The high diphthongs and high/mid, tense monophthongs occupy an intermediate position

The high vowels are rarely fully stressed Vocalic Identity Among Fully Stressed Nuclei

The high vowels are rarely fully stressed The low vowels, be they monophthongs or diphthongs, are far more likely to be fully stressed Vocalic Identity Among Fully Stressed Nuclei

The high vowels are rarely fully stressed The low vowels, be they monophthongs or diphthongs, are far more likely to be fully stressed An intermediate degree of stress accounts for the other vocalic instances Vocalic Identity Among Fully Stressed Nuclei

The high vowels are rarely fully stressed The low vowels, be they monophthongs or diphthongs, are far more likely to be fully stressed An intermediate degree of stress accounts for the other vocalic instances (but will not be addressed here) Vocalic Identity Among Fully Stressed Nuclei

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse Is It Stress? Vocalic Identity? Or What?

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse For any given vocalic class, stressed segments are longer (on average) Is It Stress? Vocalic Identity? Or What?

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse For any given vocalic class, stressed segments are longer (on average) The durational disparity is most pronounced among the low vowels and the diphthongs Is It Stress? Vocalic Identity? Or What?

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse For any given vocalic class, stressed segments are longer (on average) The durational disparity is most pronounced among the low vowels and the diphthongs Low Vowels Tend to be Much Longer in Duration than High Vowels Is It Stress? Vocalic Identity? Or What?

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse For any given vocalic class, stressed segments are longer (on average) The durational disparity is most pronounced among the low vowels and the diphthongs Low Vowels Tend to be Much Longer in Duration than High Vowels This is the case even for diphthongs Is It Stress? Vocalic Identity? Or What?

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse For any given vocalic class, stressed segments are longer (on average) The durational disparity is most pronounced among the low vowels and the diphthongs Low Vowels Tend to be Much Longer in Duration than High Vowels This is the case even for diphthongs Low Vowels are Rarely without Some Measure of Stress Accent Is It Stress? Vocalic Identity? Or What?

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse For any given vocalic class, stressed segments are longer (on average) The durational disparity is most pronounced among the low vowels and the diphthongs Low Vowels Tend to be Much Longer in Duration than High Vowels This is the case even for diphthongs Low Vowels are Rarely without Some Measure of Stress Accent This is true for monophthongs as well as diphthongs Is It Stress? Vocalic Identity? Or What?

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse For any given vocalic class, stressed segments are longer (on average) The durational disparity is most pronounced among the low vowels and the diphthongs Low Vowels Tend to be Much Longer in Duration than High Vowels This is the case even for diphthongs Low Vowels are Rarely without Some Measure of Stress Accent This is true for monophthongs as well as diphthongs High Vowels are Fully Stressed Extremely Rarely Is It Stress? Vocalic Identity? Or What?

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse For any given vocalic class, stressed segments are longer (on average) The durational disparity is most pronounced among the low vowels and the diphthongs Low Vowels Tend to be Much Longer in Duration than High Vowels This is the case even for diphthongs Low Vowels are Rarely without Some Measure of Stress Accent This is true for monophthongs as well as diphthongs High Vowels are Fully Stressed Extremely Rarely This is particularly so for monophthongs, but also applies to diphthongs Is It Stress? Vocalic Identity? Or What?

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse For any given vocalic class, stressed segments are longer (on average) The durational disparity is most pronounced among the low vowels and the diphthongs Low Vowels Tend to be Much Longer in Duration than High Vowels This is the case even for diphthongs Low Vowels are Rarely without Some Measure of Stress Accent This is true for monophthongs as well as diphthongs High Vowels are Fully Stressed Extremely Rarely This is particularly so for monophthongs, but also applies to diphthongs Thus, Stress Accent Appears to Be Intricately Involved with Vocalic Identity Is It Stress? Vocalic Identity? Or What?

Duration Appears to Play An Important (but certainly not exclusive) Role in Stress Accent for Spontaneous American English Discourse For any given vocalic class, stressed segments are longer (on average) The durational disparity is most pronounced among the low vowels and the diphthongs Low Vowels Tend to be Much Longer in Duration than High Vowels This is the case even for diphthongs Low Vowels are Rarely without Some Measure of Stress Accent This is true for monophthongs as well as diphthongs High Vowels are Fully Stressed Extremely Rarely This is particularly so for monophthongs, but also applies to diphthongs Thus, Stress Accent Appears to Be Intricately Involved with Vocalic Identity (as illustrated on the next several slides) Is It Stress? Vocalic Identity? Or What?

The Vowel Space Under (Full) Stress (Accent) There is a relatively even distribution of segments across the vowel space, with a slight bias towards the front and central vowels Canonical Vowels Only

In unaccented syllables vowels are confined largely to the high-front and high-central sectors of the articulatory space The Vowel Space Without (Stress) Accent Canonical Vowels Only

In unaccented syllables vowels are confined largely to the high-front and high-central sectors of the articulatory space The low and mid vowels “get creamed” The Vowel Space Without (Stress) Accent Canonical Vowels Only

Stress accent exerts a profound effect on the character of the vowel space The Vowel Spaces Compared Heavily AccentedUnaccented Canonical Vowels Only

Stress accent exerts a profound effect on the character of the vowel space High vowels are largely associated with unaccented syllables The Vowel Spaces Compared Heavily AccentedUnaccented Canonical Vowels Only

Stress accent exerts a profound effect on the character of the vowel space High vowels are largely associated with unaccented syllables Low vowels are mostly associated with accented forms The Vowel Spaces Compared Heavily AccentedUnaccented Canonical Vowels Only

Stress accent exerts a profound effect on the character of the vowel space High vowels are largely associated with unaccented syllables Low vowels are mostly associated with accented forms This distinction between accented and unaccented syllables is of profound importance for understanding (and modeling) pronunciation variation The Vowel Spaces Compared Heavily AccentedUnaccented Canonical Vowels Only

PART FIVE Stress Accent’s Impact on Syllable Onsets

Stress Accent and Syllable Onsets The onset is often cited as the key syllabic constituent with respect to “lexical access”

Stress Accent and Syllable Onsets The onset is often cited as the key syllabic constituent with respect to “lexical access” It is therefore of interest to ascertain how the onset’s duration behaves as a function of accent level

Stress Accent and Syllable Onsets The onset is often cited as the key syllabic constituent with respect to “lexical access” It is therefore of interest to ascertain how the onset’s duration behaves as a function of accent level Because of the onset’s key role in lexical access one might assume that its duration would be relatively stable across accent level

Stress Accent and Syllable Onsets The onset is often cited as the key syllabic constituent with respect to “lexical access” It is therefore of interest to ascertain how the onset’s duration behaves as a function of accent level Because of the onset’s key role in lexical access one might assume that its duration would be relatively stable across accent level The following slides suggest that this assumption is incorrect

Stress Accent and Syllable Onsets The onset is often cited as the key syllabic constituent with respect to “lexical access” It is therefore of interest to ascertain how the onset’s duration behaves as a function of accent level Because of the onset’s key role in lexical access one might assume that its duration would be relatively stable across accent level The following slides suggest that this assumption is incorrect, And that the structure of the onset is more complex (and more interesting) than initial intuition would suggest

Canonical Syllable Forms Onset Duration - Accent Level/Syllable Form The duration of the syllable onset varies significantly as a function of accent level (though not quite as much as in vocalic constituents)

Canonical Syllable Forms Onset Duration - Accent Level/Syllable Form The duration of the syllable onset varies significantly as a function of accent level (though not quite as much as in vocalic constituents) Onset duration is similar across syllable form (except that segments comprising complex onsets [i.e., CCVC] are slightly shorter

Canonical Syllable Forms Onset Duration - Accent Level/Syllable Form The duration of the syllable onset varies significantly as a function of accent level (though not quite as much as in vocalic constituents) Onset duration is similar across syllable form (except that segments comprising complex onsets [i.e., CCVC] are slightly shorter The duration of unaccented onsets is similar across syllable forms

Canonical Syllable Forms Onset Duration - Accent Level/Syllable Form Onsets of accented syllables are generally 50-60% longer than their unaccented counterparts

Canonical Syllable Forms Onset Duration - Accent Level/Syllable Form Onsets of accented syllables are generally 50-60% longer than their unaccented counterparts Although this durational difference is not quite as large as observed for vocalic nuclei, it is still substantial (and mostly consistent across forms)

Onset Duration and Place of Articulation It is of interest to examine accent’s impact on duration of onset (and coda) constituents in somewhat greater detail

Onset Duration and Place of Articulation It is of interest to examine accent’s impact on duration of onset (and coda) constituents in somewhat greater detail A convenient means to do so is to partition the data with respect to place of maximum articulatory constriction in order to highlight certain patterns

Onset Duration and Place of Articulation It is of interest to examine accent’s impact on duration of onset (and coda) constituents in somewhat greater detail A convenient means to do so is to partition the data with respect to place of maximum articulatory constriction in order to highlight certain patterns What is place of articulation?

Onset Duration and Place of Articulation It is of interest to examine accent’s impact on duration of onset (and coda) constituents in somewhat greater detail A convenient means to do so is to partition the data with respect to place of maximum articulatory constriction in order to highlight certain patterns What is place of articulation? Let’s find out!

Place of Articulation – A Brief Primer The tongue contacts (or nearly so) the roof of the mouth in producing many of the consonantal sounds in English Anterior Labial [p] [b] [m] Labio-dental [f] [v] Inter-dental [th] [dh] Central Alveolar [t] [d] [n] [s] [z] Posterior Palatal [sh] [zh] Velar [k] [g] [ng] Chameleon Rhoticized [r] Lateral [l] Approximant [hh] From Daniloff (1973)

Onset Duration and Place of Articulation We will examine accent’s impact on the duration of onset (and coda) constituents on the basis of articulatory place

Onset Duration and Place of Articulation We will examine accent’s impact on the duration of onset (and coda) constituents on the basis of articulatory place First, we will examine the anterior consonants, followed by the central and posterior onsets

Onset Duration and Place of Articulation We will examine accent’s impact on the duration of onset (and coda) constituents on the basis of articulatory place First, we will examine the anterior consonants, followed by the central and posterior onsets Finally, we will examine those segments whose place of articulation assimilates to that of the following vocalic segment (“place chameleons”)

Onset Duration and Place of Articulation We will examine accent’s impact on the duration of onset (and coda) constituents on the basis of articulatory place First, we will examine the anterior consonants, followed by the central and posterior onsets Finally, we will examine those segments whose place of articulation assimilates to that of the following vocalic segment (“place chameleons”) Although the heavily accented onsets are generally 50-60% longer than their unaccented counterparts …

Onset Duration and Place of Articulation We will examine accent’s impact on the duration of onset (and coda) constituents on the basis of articulatory place First, we will examine the anterior consonants, followed by the central and posterior onsets Finally, we will examine those segments whose place of articulation assimilates to that of the following vocalic segment (“place chameleons”) Although the heavily accented onsets are generally 50-60% longer than their unaccented counterparts … There is a large disparity in the durational differences due to accent level

Onset Duration and Place of Articulation We will examine accent’s impact on the duration of onset (and coda) constituents on the basis of articulatory place First, we will examine the anterior consonants, followed by the central and posterior onsets Finally, we will examine those segments whose place of articulation assimilates to that of the following vocalic segment (“place chameleons”) Although the heavily accented onsets are generally 50-60% longer than their unaccented counterparts … There is a large disparity in the durational differences due to accent level We will now examine the specific durational patterns as a function of articulatory place...

Onset Duration and Place of Articulation We will examine accent’s impact on the duration of onset (and coda) constituents on the basis of articulatory place First, we will examine the anterior consonants, followed by the central and posterior onsets Finally, we will examine those segments whose place of articulation assimilates to that of the following vocalic segment (“place chameleons”) Although the heavily accented onsets are generally 50-60% longer than their unaccented counterparts … There is a large disparity in the durational differences due to accent level We will now examine the specific durational patterns as a function of articulatory place... The patterns are revealing

Syllable Onset Duration - ANTERIOR Place Canonical Syllable Forms The voiceless consonants ([p] and [f]) are longer than the other segments

Syllable Onset Duration - ANTERIOR Place Canonical Syllable Forms The voiceless consonants ([p] and [f]) are longer than the other segments The largest durational disparity (as a function of accent level) is exhibited in the glide [y]

Syllable Onset Duration - ANTERIOR Place Canonical Syllable Forms The voiceless consonants ([p] and [f]) are longer than the other segments The largest durational disparity (as a function of accent level) is exhibited in the glide [y] The smallest durational disparity is manifest in the voiced fricative [dh]

Syllable Onset Duration - ANTERIOR Place Canonical Syllable Forms The voiceless consonants ([p] and [f]) are longer than the other segments The largest durational disparity (as a function of accent level) is exhibited in the glide [y] The smallest durational disparity is manifest in the voiced fricative [dh] The other segments exhibit intermediate patterns

Segmental Identity and Stress Accent It is of interest to compare accent’s impact on segmental duration with its impact on segmental realization (i.e., whether the segment is realized canonically or not …)

Segmental Identity and Stress Accent It is of interest to compare accent’s impact on segmental duration with its impact on segmental realization (i.e., whether the segment is realized canonically or not …) Usually, non-canonical realizations are manifest as segmental deletions

Segmental Identity and Stress Accent It is of interest to compare accent’s impact on segmental duration with its impact on segmental realization (i.e., whether the segment is realized canonically or not …) Usually, non-canonical realizations are manifest as segmental deletions The pattern of segmental realization bears some correspondence to durational variation as a function of accent level

Segmental Identity and Stress Accent It is of interest to compare accent’s impact on segmental duration with its impact on segmental realization (i.e., whether the segment is realized canonically or not …) Usually, non-canonical realizations are manifest as segmental deletions The pattern of segmental realization bears some correspondence to durational variation as a function of accent level But also exhibits some interesting differences

Segmental Identity and Stress Accent It is of interest to compare accent’s impact on segmental duration with its impact on segmental realization (i.e., whether the segment is realized canonically or not …) Usually, non-canonical realizations are manifest as segmental deletions The pattern of segmental realization bears some correspondence to durational variation as a function of accent level But also exhibits some interesting differences (which are potentially significant for models of phonetic organization)

Segmental Identity and Stress Accent It is of interest to compare accent’s impact on segmental duration with its impact on segmental realization (i.e., whether the segment is realized canonically or not …) Usually, non-canonical realizations are manifest as segmental deletions The pattern of segmental realization bears some correspondence to durational variation as a function of accent level But also exhibits some interesting differences (which are potentially significant for models of phonetic organization) Before we examine the segmental patterns in detail, a brief primer on the interpretation of these data is presented

Road Map - How to Interpret the Data Compare the numbers in the YELLOW and ORANGE columns Most numbers in the YELLOW / ORANGE columns will be similar Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Road Map - How to Interpret the Data Compare the numbers in the YELLOW and ORANGE columns Most numbers in the YELLOW / ORANGE columns will be similar Indicating that the phonetic realization of the segment is the canonical form Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Road Map - How to Interpret the Data Compare the numbers in the YELLOW and ORANGE columns Most numbers in the YELLOW / ORANGE columns will be similar Indicating that the phonetic realization of the segment is the canonical form A large disparity between columns is marked with a blue box Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Road Map - How to Interpret the Data Compare the numbers in the YELLOW and ORANGE columns Most numbers in the YELLOW / ORANGE columns will be similar Indicating that the phonetic realization of the segment is the canonical form A large disparity between columns is marked with a blue box READY? Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Road Map - How to Interpret the Data Compare the numbers in the YELLOW and ORANGE columns Most numbers in the YELLOW / ORANGE columns will be similar Indicating that the phonetic realization of the segment is the canonical form A large disparity between columns is marked with a blue box READY? OK, Let’s go! Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Onset Statistics – ANTERIOR Place Stress accent exerts relatively little affect on anterior onset segments Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Onset Statistics – ANTERIOR Place Stress accent exerts relatively little affect on anterior onset segments EXCEPT for [dh] and [y] Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Onset Statistics – ANTERIOR Place Stress accent exerts relatively little affect on anterior onset segments EXCEPT for [dh] and [y] [dh] (as in “the” and “them”) tends to delete in unaccented syllables, as does [y] (although to a lesser extent) Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Onset Duration - CENTRAL Place Canonical Syllable Forms The voiceless consonants ([t] and [s]) are longer than the other segments

Syllable Onset Duration - CENTRAL Place Canonical Syllable Forms The voiceless consonants ([t] and [s]) are longer than the other segments The alveolar flap [dx] and nasal flap [nx] are the shortest segments and don’t exhibit a durational disparity as a function of accent level

Central segments tend to “disappear” under (absence of) stress (accent) Can = Canonical form Trans = Transcribed (i.e., phonetically realized) Syllable Onset Statistics – CENTRAL Place

Central segments tend to “disappear” under (absence) of stress (accent) There is also a tendency for flaps ([dx] and [dx]) to insert under similar conditions Can = Canonical form Trans = Transcribed (i.e., phonetically realized) Syllable Onset Statistics – CENTRAL Place

Central segments tend to “disappear” under (absence) of stress (accent) There is also a tendency for flaps ([dx] and [dx]) to insert under similar conditions In heavily accented syllables, central segments maintain their canonical identity Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Onset Duration - POSTERIOR Place CANONICAL Syllable Forms The voiceless consonants ([k], [sh], [ch]) are longer than the other segments

Syllable Onset Duration - POSTERIOR Place CANONICAL Syllable Forms The voiceless consonants ([k], [sh], [ch]) are longer than the other segments Most of the segments exhibit a durational disparity between accented and unaccented forms

Syllable Onset Duration - POSTERIOR Place CANONICAL Syllable Forms The voiceless consonants ([k], [sh], [ch]) are longer than the other segments Most of the segments exhibit a durational disparity between accented and unaccented forms The duration of the voiced segments in unaccented syllables is ca ms

Syllable Onset Duration - POSTERIOR Place CANONICAL Syllable Forms The voiceless consonants ([k], [sh], [ch]) are longer than the other segments Most of the segments exhibit a durational disparity between accented and unaccented forms The duration of the voiced segments in unaccented syllables is ca ms The glide [w] exhibits a significant disparity between accented and unaccented forms

Posterior segments are remarkably stable in onset position Can = Canonical form Trans = Transcribed (i.e., phonetically realized) Syllable Onset Statistics – Posterior Place

Posterior segments are remarkably stable in onset position The only significant “deviation” from canonical representation is the intrusion of the glottal stop [q], which lacks phonemic status in English Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Onset Duration - Place Chameleons CANONICAL Syllable Forms Place chameleon segments exhibit a consistent durational disparity between accented and unaccented forms

Syllable Onset Duration - Place Chameleons CANONICAL Syllable Forms Place chameleon segments exhibit a consistent durational disparity between accented and unaccented forms In unaccented syllables the duration of these segments is ca ms

Syllable Onset Statistics – Place Chameleons “Chameleons” assimilate their place of articulation to the following vowel Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Onset Statistics – Place Chameleons “Chameleons” assimilate their place of articulation to the following vowel They are relatively stable at syllable onset, except in unaccented forms Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Onset Statistics – Place Chameleons “Chameleons” assimilate their place of articulation to the following vowel They are relatively stable at syllable onset, except in unaccented forms The reduced form of [l] is [lg], a glide-like element – it tends to assume the functional status of [l] in unaccented syllables Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Pronunciation Patterns – Syllable Onsets The ANTERIOR and POSTERIOR onsets are generally canonically realized (the exceptions typically function as “junctures,” rather than as segments) C = Canonical realization N = Non-canonical realization, N 0 = Non-canonical in unaccented syllables Place of ArticulationApproximants

Pronunciation Patterns – Syllable Onsets The ANTERIOR and POSTERIOR onsets are generally canonically realized (the exceptions typically function as “junctures,” rather than as segments) The CENTRAL and PLACE CHAMELEON onsets are often non-canonical (and also often function as “junctures”) C = Canonical realization N = Non-canonical realization, N 0 = Non-canonical in unaccented syllables Place of ArticulationApproximants

PART SIX Stress Accent’s Impact on Syllable Codas

Stress Accent and Syllable Codas Stress accent’s impact on syllable codas differs from that of onsets

Stress Accent and Syllable Codas Stress accent’s impact on syllable codas differs from that of onsets The disparity in duration between accented and unaccented forms tends to be significantly less for codas than for onsets (at least when deletions are NOT taken into account)

Stress Accent and Syllable Codas Stress accent’s impact on syllable codas differs from that of onsets The disparity in duration between accented and unaccented forms tends to be significantly less for codas than for onsets (at least when deletions are NOT taken into account) There is a far greater probability of segmental deletion in coda constituents

Stress Accent and Syllable Codas Stress accent’s impact on syllable codas differs from that of onsets The disparity in duration between accented and unaccented forms tends to be significantly less for codas than for onsets (at least when deletions are NOT taken into account) There is a far greater probability of segmental deletion in coda constituents Accent level exerts a powerful influence on segmental deletion and on segmental duration

Stress Accent and Syllable Codas Stress accent’s impact on syllable codas differs from that of onsets The disparity in duration between accented and unaccented forms tends to be significantly less for codas than for onsets (at least when deletions are NOT taken into account) There is a far greater probability of segmental deletion in coda constituents Accent level exerts a powerful influence on segmental deletion and on segmental duration To a certain degree segmental deletion and duration interact (or are flip sides of the same phonetic coin)

Stress Accent and Syllable Codas Stress accent’s impact on syllable codas differs from that of onsets The disparity in duration between accented and unaccented forms tends to be significantly less for codas than for onsets (at least when deletions are NOT taken into account) There is a far greater probability of segmental deletion in coda constituents Accent level exerts a powerful influence on segmental deletion and on segmental duration To a certain degree segmental deletion and duration interact (or are flip sides of the same phonetic coin) (for this reason the durational properties of ALL syllables, including those in which coda segments are deleted, are also shown)

Syllable Coda Duration - ANTERIOR Place CANONICAL Syllable Forms The durational disparity between accented and unaccented forms is smaller for codas and for onsets

Syllable Coda Duration - ANTERIOR Place CANONICAL Syllable Forms The durational disparity between accented and unaccented forms is smaller for codas and for onsets Certain segments exhibit little if any difference in duration as a function of accent (e.g., [b], [m], [v])

Syllable Coda Duration - ANTERIOR Place CANONICAL Syllable Forms The durational disparity between accented and unaccented forms is smaller for codas and for onsets Certain segments exhibit little if any difference in duration as a function of accent (e.g., [b], [m], [v]) Such segments manifest certain properties of flaps

Syllable Coda Duration - ANTERIOR Place ALLSyllable Forms Because of the significant number of deletions in coda constituents, particularly in unaccented syllables, the durational disparity between accented and unaccented syllables is preserved when duration is computed across ALL syllable forms (including those with deletions)

Syllable Coda Duration - ANTERIOR Place ALLSyllable Forms Because of the significant number of deletions in coda constituents, particularly in unaccented syllables, the durational disparity between accented and unaccented syllables is preserved when duration is computed across ALL syllable forms (including those with deletions) Those segments exhibiting flap-like properties (e.g., [b], [m], [v]) tend to delete the most in unaccented codas

Syllable Coda Statistics – Anterior Place Anterior coda segments are relatively stable under stress (accent) Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Statistics – Anterior Place Anterior coda segments are relatively stable under stress (accent) The segments [m] and [v] are exceptions Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Statistics – Anterior Place Anterior coda segments are relatively stable under stress (accent) The segments [m] and [v] are exceptions – they often function as “flaps” in this context, and Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Statistics – Anterior Place Anterior coda segments are relatively stable under stress (accent) The segments [m] and [v] are exceptions – they often function as “flaps” in this context, and They tend to delete in unaccented syllables Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Duration - CENTRAL Place CANONICAL Syllable Forms The centrally articulated codas exhibit a high probability of deletion, particularly in unaccented syllables (see durational data for ALL syllables)

Syllable Coda Duration - CENTRAL Place CANONICAL Syllable Forms The centrally articulated codas exhibit a high probability of deletion, particularly in unaccented syllables (see durational data for ALL syllables) The duration of many of the coda segments do not exhibit a difference in duration (when computed for the canonical syllable forms)

Syllable Coda Duration - CENTRAL Place CANONICAL Syllable Forms The centrally articulated codas exhibit a high probability of deletion, particularly in unaccented syllables (see durational data for ALL syllables) The duration of many of the coda segments do not exhibit a difference in duration (when computed for the canonical syllable forms) Most of the unaccented codas are short in duration

Syllable Coda Duration - CENTRAL Place ALL Syllable Forms Because of the high probability of deletions for central coda consonants the mean durations are quite low relative to other conditions

Syllable Coda Duration - CENTRAL Place ALL Syllable Forms Because of the high probability of deletions for central coda consonants the mean durations are quite low relative to other conditions In some sense the default duration for central codas is very short (more on this point later on in the presentation)

Syllable Coda Statistics – Central Place Central coda segments are extremely unstable under stress (accent) Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Statistics – Central Place Central coda segments are extremely unstable under stress (accent) (except for the fricatives [s] and [z]) Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Statistics – Central Place Central coda segments are extremely unstable under stress (accent) (except for the fricatives [s] and [z]) The segments [t], [d] and [n] tend to delete in coda position, even in heavily accented syllables Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Statistics – Central Place Central coda segments are extremely unstable under stress (accent) (except for the fricatives [s] and [z]) The segments [t], [d] and [n] tend to delete in coda position, even in heavily accented syllables The major effect of stress accent is its affect on the probability of segmental deletion (which is appreciably higher in unaccented forms) Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Duration - POSTERIOR Place CANONICAL Syllable Forms Many coda consonants are short in duration

Syllable Coda Duration - POSTERIOR Place CANONICAL Syllable Forms Many coda consonants are short in duration Most segments exhibit relatively little sensitivity to accent level

Syllable Coda Duration - POSTERIOR Place ALL Syllable Forms There are relatively few deletions in coda segments, hence the durational patterns are similar for ALL syllable forms relative to the canonical syllable forms

Syllable Coda Statistics – Posterior Place Posterior coda segments are relatively stable under stress (accent) Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Statistics – Posterior Place Posterior coda segments are relatively stable under stress (accent) The primary exception is [ng], which tends to delete in unaccented syllables Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Statistics – POSTERIOR Place Posterior coda segments are relatively stable under stress (accent) The primary exception is [ng], which tends to delete in unaccented syllables The “infamous” glottal stop [q] tends to insert in this context Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Duration - Place Chameleons CANONICAL Syllable Forms There is a large durational disparity between the accented and unaccented chameleon segments

Syllable Coda Duration - Place Chameleons CANONICAL Syllable Forms There is a large durational disparity between the accented and unaccented chameleon segments In unaccented syllables the duration of these segments is ca. 60 ms

Syllable Coda Duration - Place Chameleons ALL Syllable Forms There are a lot of deletions of coda chameleons in unaccented syllables

Syllable Coda Duration - Place Chameleons ALL Syllable Forms There are a lot of deletions of coda chameleons in unaccented syllables Hence the mean duration of these segments in unaccented forms is short

Syllable Coda Statistics – Place Chameleons Chameleon segments are unstable under stress (accent) Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Statistics – Place Chameleons Chameleon segments are unstable under stress (accent) This is particularly true for [l] (for all levels of accent), where many canonical segments transmute into [lg], particularly in accented forms Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Syllable Coda Statistics – Place Chameleons Chameleon segments are unstable under stress (accent) This is particularly true for [l] (for all levels of accent), where many canonical segments transmute into [lg], particularly in accented forms The segment [r] tends to delete in unaccented syllables, but not otherwise Can = Canonical form Trans = Transcribed (i.e., phonetically realized)

Pronunciation Patterns – Syllable Codas The ANTERIOR and POSTERIOR codas are generally canonically realized (the exceptions typically function as “junctures,” rather than segments) C = Canonical realization N = Non-canonical realization, N 0 = Non-canonical in unaccented syllables Place of ArticulationApproximants

Pronunciation Patterns – Syllable Codas The ANTERIOR and POSTERIOR codas are generally canonically realized (the exceptions typically function as “junctures,” rather than segments) The CENTRAL and PLACE CHAMELEON segments are often non-canonical (and also often function as “junctures”) C = Canonical realization N = Non-canonical realization, N 0 = Non-canonical in unaccented syllables Place of ArticulationApproximants

PART SEVEN Onset and Coda Patterns Compared

Comparison of Syllable Onsets and Codas Onsets tend to be more stable than codas C = Canonical realization N = Non-canonical realization, N 0 = Non-canonical in unaccented syllables Place of ArticulationApproximants

Comparison of Syllable Onsets and Codas Onsets tend to be more stable than codas The centrally articulated segments are highly unstable in both contexts C = Canonical realization N = Non-canonical realization, N 0 = Non-canonical in unaccented syllables Place of ArticulationApproximants

Comparison of Syllable Onsets and Codas Onsets tend to be more stable than codas The centrally articulated segments are highly unstable in both contexts As are the place chameleons C = Canonical realization N = Non-canonical realization, N 0 = Non-canonical in unaccented syllables Place of ArticulationApproximants

Comparison of Syllable Onsets and Codas Onsets tend to be more stable than codas The centrally articulated segments are highly unstable in both contexts As are the place chameleons The unstable anterior and posterior phones are mostly “junctures” C = Canonical realization N = Non-canonical realization, N 0 = Non-canonical in unaccented syllables Place of ArticulationApproximants

PART EIGHT A Preliminary Juncture-Accent Model

A means of visualizing important properties of the acoustic signal Road Map to the Juncture-Accent Model

A means of visualizing important properties of the acoustic signal The juncture-accent representation is based on log, critical-band energy across time and frequency Road Map to the Juncture-Accent Model

A means of visualizing important properties of the acoustic signal The juncture-accent representation is based on log, critical-band energy across time and frequency Although it is not intended as an auditory representation, it does represent spectro-temporal properties of the signal in a manner consistent with auditory principles Road Map to the Juncture-Accent Model

A means of visualizing important properties of the acoustic signal The juncture-accent representation is based on log, critical-band energy across time and frequency Although it is not intended as an auditory representation, it does represent spectro-temporal properties of the signal in a manner consistent with auditory principles Let’s take a look at some illustrations – Spectro-Temporal Profiles or “STePs” Road Map to the Juncture-Accent Model

Anatomy of a Spectro-Temporal Profile [s] [eh] [vx] [en] juncture accented syllable unaccented syllable “Seven” mean duration Full-spectrum perspective OGI Numbers95 [s] [eh] [vx] [en]

[s] [eh] [vx] [en] juncture accented syllable unaccented syllable mean duration “Seven” Anatomy of a Spectro-Temporal Profile High-frequency perspective OGI Numbers95 [s] [eh] [vx] [en]

Anatomy of a Spectro-Temporal Profile juncture accented syllable unaccented syllable [z] mean duration “Zero” [ih] [r] [ax] Full-spectrum perspective OGI Numbers95 [z] [ih] [r] [ah]

Spectro-Temporal Profile juncture unaccented syllable mean duration “Zero” [ih] [r] [ax] accented syllable [z] High-frequency perspective OGI Numbers95 [z] [ih] [r] [ah]

Spectro-Temporal Profile mean duration “Three” [iy] [r] accented syllable [th] Full-spectrum perspective OGI Numbers95 [th] [r] [iy]

Spectro-Temporal Profile mean duration “Three” [r] accented syllable [iy] High-frequency perspective OGI Numbers95 [th] [th] [r] [iy]

Summary and Conclusions (at last!)

Summary and Conclusions Based on a detailed analysis of a manually annotated corpus of spontaneous American English (Switchboard) the following conclusions are drawn:

Summary and Conclusions Based on a detailed analysis of a manually annotated corpus of spontaneous American English (Switchboard) the following conclusions are drawn: Stress accent is the primary linguistic property associated with duration at the segmental, syllabic and lexical levels

Summary and Conclusions Based on a detailed analysis of a manually annotated corpus of spontaneous American English (Switchboard) the following conclusions are drawn: Stress accent is the primary linguistic property associated with duration at the segmental, syllabic and lexical levels Stress accent’s impact on duration is most pronounced in the vocalic nucleus

Summary and Conclusions Based on a detailed analysis of a manually annotated corpus of spontaneous American English (Switchboard) the following conclusions are drawn: Stress accent is the primary linguistic property associated with duration at the segmental, syllabic and lexical levels Stress accent’s impact on duration is most pronounced in the vocalic nucleus But also affects the duration of the syllable onset

Summary and Conclusions Based on a detailed analysis of a manually annotated corpus of spontaneous American English (Switchboard) the following conclusions are drawn: Stress accent is the primary linguistic property associated with duration at the segmental, syllabic and lexical levels Stress accent’s impact on duration is most pronounced in the vocalic nucleus But also affects the duration of the syllable onset The duration of the syllable coda is less affected by stress accent, however...

Summary and Conclusions Based on a detailed analysis of a manually annotated corpus of spontaneous American English (Switchboard) the following conclusions are drawn: Stress accent is the primary linguistic property associated with duration at the segmental, syllabic and lexical levels Stress accent’s impact on duration is most pronounced in the vocalic nucleus But also affects the duration of the syllable onset The duration of the syllable coda is less affected by stress accent, however... Coda constituents are more prone to deletion as a function of stress accent

Summary and Conclusions Based on a detailed analysis of a manually annotated corpus of spontaneous American English (Switchboard) the following conclusions are drawn: Stress accent is the primary linguistic property associated with duration at the segmental, syllabic and lexical levels Stress accent’s impact on duration is most pronounced in the vocalic nucleus But also affects the duration of the syllable onset The duration of the syllable coda is less affected by stress accent, however... Coda constituents are more prone to deletion as a function of stress accent Thus, stress accent has an (indirect) impact on duration even for codas (via segmental deletion)

Summary and Conclusions Based on a detailed analysis of a manually annotated corpus of spontaneous American English (Switchboard) the following conclusions are drawn: Stress accent is the primary linguistic property associated with duration at the segmental, syllabic and lexical levels Stress accent’s impact on duration is most pronounced in the vocalic nucleus But also affects the duration of the syllable onset The duration of the syllable coda is less affected by stress accent, however... Coda constituents are more prone to deletion as a function of stress accent Thus, stress accent has an (indirect) impact on duration even for codas (via segmental deletion) These data are inconsistent with a segmental model of spoken language

Summary and Conclusions Based on a detailed analysis of a manually annotated corpus of spontaneous American English (Switchboard) the following conclusions are drawn: Stress accent is the primary linguistic property associated with duration at the segmental, syllabic and lexical levels Stress accent’s impact on duration is most pronounced in the vocalic nucleus But also affects the duration of the syllable onset The duration of the syllable coda is less affected by stress accent, however... Coda constituents are more prone to deletion as a function of stress accent Thus, stress accent has an (indirect) impact on duration even for codas (via segmental deletion) These data are inconsistent with a segmental model of spoken language But is consistent with a JUNCTURE-ACCENT model based on syllable forms of variable accent level

That’s All, Folks Many Thanks for Your Time and Attention

What’s Going on in Pronunciation?

With respect to onset and coda segments (i.e. consonants) there are two basic forms – (1) those that are relatively stable across accent level, and (2) those that are not What’s Going On? (in pronunciation)

With respect to onset and coda segments (i.e. consonants) there are two basic forms – (1) those that are relatively stable across accent level, and (2) those that are not Most of the non-continuants (i.e. stops and nasals) are stable when the locus of articulation constriction is either anterior or posterior What’s Going On? (in pronunciation)

With respect to onset and coda segments (i.e. consonants) there are two basic forms – (1) those that are relatively stable across accent level, and (2) those that are not Most of the non-continuants (i.e. stops and nasals) are stable when the locus of articulation constriction is either anterior or posterior The centrally articulated stops and nasals are highly unstable, particularly in coda position and in unaccented syllables What’s Going On? (in pronunciation)

With respect to onset and coda segments (i.e. consonants) there are two basic forms – (1) those that are relatively stable across accent level, and (2) those that are not Most of the non-continuants (i.e. stops and nasals) are stable when the locus of articulation constriction is either anterior or posterior The centrally articulated stops and nasals are highly unstable, particularly in coda position and in unaccented syllables The place chameleons (i.e., the approximants) are not very stable in either onset or coda position What’s Going On? (in pronunciation)

With respect to onset and coda segments (i.e. consonants) there are two basic forms – (1) those that are relatively stable across accent level, and (2) those that are not Most of the non-continuants (i.e. stops and nasals) are stable when the locus of articulation constriction is either anterior or posterior The centrally articulated stops and nasals are highly unstable, particularly in coda position and in unaccented syllables The place chameleons (i.e., the approximants) are not very stable in either onset or coda position The vowels are divisible into two main groups – accented and unaccented What’s Going On? (in pronunciation)

With respect to onset and coda segments (i.e. consonants) there are two basic forms – (1) those that are relatively stable across accent level, and (2) those that are not Most of the non-continuants (i.e. stops and nasals) are stable when the locus of articulation constriction is either anterior or posterior The centrally articulated stops and nasals are highly unstable, particularly in coda position and in unaccented syllables The place chameleons (i.e., the approximants) are not very stable in either onset or coda position The vowels are divisible into two main groups – accented and unaccented The accented vowels are generally canonically realized and quasi-evenly distributed across the vowel space What’s Going On? (in pronunciation)

With respect to onset and coda segments (i.e. consonants) there are two basic forms – (1) those that are relatively stable across accent level, and (2) those that are not Most of the non-continuants (i.e. stops and nasals) are stable when the locus of articulation constriction is either anterior or posterior The centrally articulated stops and nasals are highly unstable, particularly in coda position and in unaccented syllables The place chameleons (i.e., the approximants) are not very stable in either onset or coda position The vowels are divisible into two main groups – accented and unaccented The accented vowels are generally canonically realized and quasi-evenly distributed across the vowel space The unaccented forms tend to concentrate in the high-front and high-central regions of the vowel space What’s Going On? (in pronunciation)

With respect to onset and coda segments (i.e. consonants) there are two basic forms – (1) those that are relatively stable across accent level, and (2) those that are not Most of the non-continuants (i.e. stops and nasals) are stable when the locus of articulation constriction is either anterior or posterior The centrally articulated stops and nasals are highly unstable, particularly in coda position and in unaccented syllables The place chameleons (i.e., the approximants) are not very stable in either onset or coda position The vowels are divisible into two main groups – accented and unaccented The accented vowels are generally canonically realized and quasi-evenly distributed across the vowel space The unaccented forms tend to concentrate in the high-front and high-central regions of the vowel space Certain segments are actually junctures – e.g., the flaps and the glottal stop What’s Going On? (in pronunciation)

With respect to onset and coda segments (i.e. consonants) there are two basic forms – (1) those that are relatively stable across accent level, and (2) those that are not Most of the non-continuants (i.e. stops and nasals) are stable when the locus of articulation constriction is either anterior or posterior The centrally articulated stops and nasals are highly unstable, particularly in coda position and in unaccented syllables The place chameleons (i.e., the approximants) are not very stable in either onset or coda position The vowels are divisible into two main groups – accented and unaccented The accented vowels are generally canonically realized and quasi-evenly distributed across the vowel space The unaccented forms tend to concentrate in the high-front and high-central regions of the vowel space Certain segments are actually junctures – e.g., the flaps and the glottal stop Many so-called segments are actually junctures (as they are flaps), the most noteworthy examples are [dh] and [v] What’s Going On? (in pronunciation)

With respect to onset and coda segments (i.e. consonants) there are two basic forms – (1) those that are relatively stable across accent level, and (2) those that are not Most of the non-continuants (i.e. stops and nasals) are stable when the locus of articulation constriction is either anterior or posterior The centrally articulated stops and nasals are highly unstable, particularly in coda position and in unaccented syllables The place chameleons (i.e., the approximants) are not very stable in either onset or coda position The vowels are divisible into two main groups – accented and unaccented The accented vowels are generally canonically realized and quasi-evenly distributed across the vowel space The unaccented forms tend to concentrate in the high-front and high-central regions of the vowel space Certain segments are actually junctures – e.g., the flaps and the glottal stop Many so-called segments are actually junctures (as they are flaps), the most noteworthy examples are [dh] and [v] None of these properties is consistent with a segmental model of language What’s Going On? (in pronunciation)

Syllable Duration and Number of Segments For syllables greater than a single segment there is relatively little difference in duration as the number of segments (within a syllable) increases Canonical Syllable Forms

Syllable Duration and Number of Segments For syllables greater than a single segment there is relatively little difference in duration as the number of segments (within a syllable) increases Suggesting that syllable duration is largely controlled by processes independent of segmental production Canonical Syllable Forms