Speech Production1 Articulation and Resonance Vocal tract as resonating body and sound source. Acoustic theory of vowel production.

Speech Production2 Basic Anatomy Review

Speech Production3 Basic Anatomy Review

Speech Production4 Basic Anatomy Review

Speech Production5 Vocal tract as resonating body and sound source. Phonation sound source is VF vibration. Vocal tract is 1/4 wavelength resonator –17 cm long in the average adult male. –Open end is mouth and closed end is vocal folds. –There are a number of secondary 1/4 wavelength resonators due to changes in tube diameter.

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7 Acoustic (Source) Theory of Vowel Production Source Filter

Speech Production8 Source Source of all vowels is vocal fold vibration Source creates fo and harmonics Harmonics are attenuated with an increase in frequency

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10 Filter Filters modify the intensity of harmonics Remember… The vocal tract a 17 cm 1/4 WL resonator and has a primary resonant frequency of 500 Hz & secondary resonant frequencies at 1500 and 2500 Hz. Transfer function shows effects of vocal tract resonance.

Speech Production11 Insert figure 4.62

Speech Production12 Interaction between source and filter In real world there are additional resonances which interact in vowel production. Every time you change vocal tract configuration you change resonant peaks. You also have radiation effect which results in 6 dB/octave increase in high frequencies. All these factors interact to produce a vowel.

Speech Production13 Interaction between source and filter

Speech Production14 In above example resonant peaks are labeled F1, F2, & F3. These are known as formant frequencies. Formant frequencies can be displayed on a Spectrogram which shows frequency on ordinate and time on abscissa.

Speech Production15 English Speech Sounds Vowels & Diphthongs Semivowels Nasals Stops Fricatives Affricates Sound Influence Suprasegmentals

Speech Production16 Vowels Vowels classified by tongue and mandible position. High front vowels Low back vowels High back vowels

Speech Production17 High Front Vowels Include Tongue placed high and forward in vocal tact Mandible somewhat closed High oral constriction

Speech Production18 Low back vowels Tongue constriction occurring to the rear of vocal tract Mandible opening is wide. Pharyngeal constriction is greater than other vowels.

Speech Production19 High back vowels Tongue constriction in back of vocal tract. Mandible is somewhat closed. Lips are somewhat protruded.

Speech Production20 Vowel Quadrilateral

Speech Production21 Vowels may be displayed showing formant frequencies

Speech Production22 Spectrograms of Some Vowels

Speech Production23 Diphthongs Vowels of changing resonance On next slide we have examples of diphthongs. Notice how F1 and F2 transitions between first and second vowel.

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Speech Production26 Diphthongs (continued) Peterson and Lehiste call shorter diphthongs Tense Monophthongs. These include diphthongs found in “bay and boat” Longer diphthongs are those found in “find, bout, boy”

Speech Production27 Semivowel production Four semivowels /w, j, r, l/ Similar to vowels because they are highly resonant. Considered to be consonants because they function in language to release the vowel or diphthong. E.g., “swim” is possible “swm” is not.

Speech Production28 Semivowels (continued) Two classes of semivowels… –Glides /j, w/ –Liquids /l, r/

Speech Production29 Semivowels (continued) Glides… –are so named because the formants glide to and from adjacent vowels. Very similar to a diphthong except it has a much faster transition. –In terms of place of production … /j/ is considered a palatal glide /w/ is labial glide

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Speech Production31 Semivowels (continued) Liquids… –Involve placing tongue tip either close to or near the alveolar ridge. –/r/ - tongue tip does not touch alveolar ridge while airflow passes centrally through a grooved tongue. –Some dialects omit /r/ –/w/ for /r/ substitution is common since /w/ is easier to produce.

Speech Production32 Semivowels (continued) /l/ - tongue tip touches alveolar ridge while airflow passes laterally. In initial position /l/ is produced as speaker releases the tongue. In the final position it is of long duration. /l/ of long duration are sometimes referred to as a “dark /l/”

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Speech Production34 Nasals Include /m/, /n/, and /ng/ Anti-resonances … need to discuss prior to actual nasal production. –Opposite of resonance. Attenuates a range of frequencies. –All nasals have anti-resonances which are a result of a cul-de-sac formed by closed vocal tract.

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Speech Production36 Nasals (continued) Place of articulation has a direct effect on size of cul-de-sac and anti-resonant frequency. The place of artic and anti-resonant frequency for each nasal is as follows...

Speech Production37 Nasals (continued) Other characteristics include … –All air passes through nasal cavity. –Because air passes through nasal cavity (longer pathway than oral tract) you have a lower resonant frequency than non-nasals. –Nasals have relatively low intensity, especially for upper formants.