2. Fricatives + Voice Onset Time November 25, 2015

3. In the Year 2000 Today: we’ll wrap up fricatives… and then move on to stops. This Friday, there will be one final transcription exercise. On Bengali and Arabic. I posted it on Monday night. The final production exercise (on stops and fricatives) will be posted after this lecture.

4. 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”

5. 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:

6. Palatography [kasa]

7. Palatography

8. Polish Clusters Just for kicks...

9. Four Fricatives

10. Mandarin Sibilants Mandarin Chinese also has dental, post-alveolar and alveolo-palatal sibilant fricatives. The post-alveolars are sometimes retroflex

11. Mandarin

12. Affricates Affricates are transcribed as stop-fricative sequences Acoustically, amplitude rises faster in affricates than in plain fricatives “rise time” Phonologically, affricates are [-continuant]

13. Affricate Typology More numbers from the UPSID database: 522 affricates in 316 languages 141 [ts]95 80 [dz]30 485 affricates have sibilant fricatives Other affricate types are rarer: [pf] (German)[tx] (Navajo)

14. Fricative vs. Affricate “shy” “chime”

15. Polish, Again Polish contrasts affricates with stop + fricative sequences

16. Stop + Fricative vs. Affricate

17. 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

18. 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…

19. 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

20. Aspiration in Quechua Acoustically, this distinction translates to: longer duration of aspiration (aspirated) shorter duration of aspiration (voiceless/unaspirated)

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

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

23. 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.

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

25. 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  50 - 150 milliseconds

26. 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  0 - 20 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…

27. Thai Stops

28. [ba] [pa]

29. English Stop Contrasts 1.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)

30. Beak, Peak, Speak

31. Rabid vs. Rapid

32. English Stop Contrasts 4. In syllable-final position: vowels preceding /p/ are short vowels preceding /b/ are longer /p/ closure tends to be longer than /b/ closure Moral of the story: Phonological voiced vs. voiceless contrast in English is abstract It has different phonetic manifestations in different contexts. Lisker & Abramson suggested describing the contrast as “fortis” vs. “lenis”, rather than “voiced” vs. “voiceless”.

33. By the way… There is no a priori reason why stops can’t be pre- aspirated. In fact, Icelandic does this all the time:

34. More Icelandica Lots of languages devoice obstruents in final position… Icelandic devoices sonorants, too.

35. Complication #1 Fricatives and affricates may also be aspirated In these cases, VOT must be calculated beginning from the offset of sibilance.

37. Tree vs. Chree Check ‘em out in Praat

38. The Four-Way Another problem with the VOT analysis is that it cannot straightforwardly account for the four-way voicing distinctions found in languages like Hindi. These languages distinguish between (breathy) voiced aspirated and voiceless aspirated stops and affricates.

39. [p h al]

40. Hindi Bengali [d h ol] voiced + breathy aspirated voiced + aspirated

41. Zhu|hoasi Stop Contrasts Zhu|hoasi is spoken in northern Namibia.

42. Syllable-Final Syllable-final obstruents may also be distinguished by aspiration. In this case, voicing does not necessarily resume after aspiration Examples from Armenian

43. Syllable-Final Spectrograms release burst aspiration

44. Practical Point: Pop Filters When recording speech digitally, the airflow of aspiration can cause “pops” to appear in the recording. A result of clipping the waveform If you have some extra cash, this problem can be solved by placing a pop filter in front of the microphone. Otherwise, make sure the microphone is not directly in front of the speaker’s lips.