Fricatives + VOT April 6, 2010

For Starters… A note on perceptual verbiage. Also note: I gave you the wrong CP data!

Incorrect Sensitivity

Incorrect Bias

Correct Sensitivity

Correct Bias

Where were we? [s] Let’s check the ultrasound…

Secondary Articulations What effect might lowering the center of the tongue have on formant values? (think: perturbation theory) Check it out in Praat.

Secondary Articulations A secondary articulation is made by superimposing a glide-like articulation on top of another constriction elsewhere in the vocal tract. Two constrictions with an unequal degree of closure: primary articulation: more constricted secondary articulation: less constricted The most common secondary articulations are: [ w ]labialization [ j ]palatalization velarization (think: the Beatles) pharyngealization

Secondary Timing Secondary articulations differ from glides primarily in terms of timing. [k w ]: peak of labial protrusion occurs during stop closure [kw]: peak of labial protrusion occurs after stop closure [k] [w][w] [w] velum lips velum lips

Pharyngealization Consonants are pharyngealized by superimposing a pharynx narrowing gesture on the regular consonant articulation. Mid-sagittal diagrams from Arabic: What effect would this have on formant frequencies?

Arabic Examples Arabic contrasts pharyngealized and non-pharyngealized consonants.

[t] vs. [ti:n] Pharyngeal constrictions raise F1 and lower F2 an -like formant pattern

More Secondary Examples Susie and David say “speech”: Also: Tina Fey is “shtraight” Note: there are no word-initial /sr/ sequences in English. “shriek”*“sreek”

Whistling Fricatives Shona (spoken in Zimbabwe) has “whistling fricatives” = retroflex fricatives produced with lip-rounding “exp.”“arrive” “owl”“these” “to provoke”“to blame” “to become full” “to give birth”

The Politics of Frication Denture-wearers often produce whistling fricatives, too. Barack Obama John McCain Excited speakers of English can even produce pharyngeal fricatives… like Keith Olbermann:

Back to Enhancement Note: lip-rounding can be used to enhance other fricative contrasts In Polish, it enhances the contrast between (post-)alveolar and dental fricatives the (post-)alveolars have the rounding

Polish, continued Polish also has what are known as alveolo-palatal fricatives. = constriction in the post-alveolar region + raised tongue in the palatal region (behind the fricative)

Polish Sibilants

vs.

Palatography [kasa]

Palatography

Polish Clusters Just for kicks...

Four Fricatives

Affricates Affricates are transcribed as stop-fricative sequences Acoustically, amplitude rises faster in affricates than in plain fricatives “rise time” Although fricative duration seems to be shorter in affricates, too. Phonologically, affricates are [-continuant]

Fricative vs. Affricate “shy” “chime”

Polish, Again Polish contrasts affricates with stop + fricative sequences

Stop + Fricative vs. Affricate

Fricative Acoustics Summary Turbulence provides the source of fricative noise Voiced fricatives also have a sound source at the glottis Obstacle turbulence tends to be louder than channel turbulence Sibilants are particulary high in intensity The filter of fricative turbulence noise changes depending on the place of articulation sibilants: very short filter, emphasizing high frequencies labials: essentially no filter (flat spectrum) back fricatives: longer, more vowel-like filter Affricates: stop-fricative sequences with shorter rise time

Aerodynamics Recall that: voiced fricatives are more difficult to produce than voiceless fricatives. Likewise: voiced stops are more difficult to produce than voiceless stops. Why? Voicing requires a pressure drop across the glottis.  Pressure below > Pressure above Airflow into the mouth, behind a stop closure, inherently increases the air pressure above the glottis…

Timing Stop voicing is inherently unsustainable.  The voiced/voiceless distinction in stops often takes a different form: = unaspirated vs. aspirated An aspirated stop has the following timing: 1.Stop closure is made 2.Airflow builds up pressure behind closure 3.Closure is released (with a “burst”) 4.Air flows unimpeded through glottis (“aspiration” = [ h ]) 5.Vocal folds close; voicing begins

Aspiration in Quechua Also: let’s play with fire! Acoustically, this distinction translates to: longer duration of aspiration (aspirated) shorter duration of aspiration (voiceless/unaspirated)

Quechua: Aspirated release burst aspiration voicing (vowel) In this example, the aspiration lasts for ~ 135 ms

Quechua: Unaspirated release burst aspiration voicing (vowel) In this example, the aspiration lasts for ~ 35 ms

An Unvoiced Stop: [pøt h ] release burst voicing (vowel) Dutch, on the other hand, contrasts between truly voiced and unvoiced stops in syllable onset position. Here, vowel voicing begins ~ 7 ms after the release burst.

A Voiced Stop: [byt h ] release burst voicing (vowel)voicing (closure) In this case, voicing begins 85 ms before the release burst.

Voice Onset Time Some languages contrast between voiced and unvoiced stops; others contrast between aspirated and unaspirated stops.. Lisker & Abramson (1964) collapsed the two distinctions onto one continuum, defined by Voice Onset Time (VOT) = the length of time between the release of a stop closure and the onset of voicing. For aspirated stops--voicing begins after the release, so: VOT  milliseconds

Voice Onset Time Voice Onset Time (VOT) = the length of time between the release of a stop closure and the onset of voicing. For unaspirated stops--voicing begins at the release, so: VOT  milliseconds For voiced stops--voicing begins before the release, so: VOT < 0 milliseconds (VOT can be negative) This enabled Lisker & Abramson to easily account for the three-way voicing distinctions found in languages like Thai…

Thai Stops

[ba] [pa] Lisker & Abramson determined early on that VOT distinctions were perceived categorically…

VOT distributions Specific VOT values fall within a range for each voicing type, within a language.

Cross-Linguistically Ladefoged and Cho (1999) found that the average VOT of aspirated stops varies considerably from language to language.  There is no universal phonology-to-phonetics translation of aspiration.

English Stop Contrasts The phonetic implementation of “voicing” contrasts may also vary by syllabic context. 1.For example, in English, In onset position: /p/ is voiceless aspirated /b/ is voiceless unaspirated 2.In medial position (between voiced segments): /p/ is voiceless unaspirated /b/ is voiced 3.After /s/, in the same syllable: only voiceless unaspirated stops (no contrast)

Check it out In Praat: beak, peak, speak Also: rabid vs. rapid