1 / 28

Voice Onset Time + Voice Quality

Voice Onset Time + Voice Quality. November 28, 2011. The Future. Production Exercise #3 is due. This week: the basics of obstruent acoustics On Wednesday: cues for place of articulation. On Friday: more spectrogram matching. Next week: sonorant acoustics approximants and nasals

marcin
Télécharger la présentation

Voice Onset Time + Voice Quality

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Voice Onset Time+ Voice Quality November 28, 2011

  2. The Future • Production Exercise #3 is due. • This week: the basics of obstruent acoustics • On Wednesday: cues for place of articulation. • On Friday: more spectrogram matching. • Next week: sonorant acoustics • approximants and nasals • Production Exercise #4 for Wednesday the 7th.

  3. Review: Stops and Voicing • Stops • Three stages: close, maintain, release • Pressure build-up behind closure • “Release Burst” • Voicing • Vocal folds are lightly brought together (adducted) • Sub-glottal pressure higher than supra-glottal pressure • Airflow through glottis causes cycle of vocal fold opening and closing • Voiceless: k > t > p Voiced: b > d > g

  4. It’s not that simple • The voicing of stops is difficult, so the contrast between voiced and voiceless stops often takes a different form • Making use of a different property: aspiration • An aspirated stop has the following timing: • Stop closure is made • Airflow builds up pressure behind closure • Closure is released (with a “burst”) • Air flows unimpeded through glottis (“aspiration”) • Vocal folds close; voicing begins

  5. An Aspirated Stop: [phœt] aspiration release burst [t] release burst voicing (vowel) [t] closure

  6. An Unaspirated Stop: [pœt] voicing (vowel) release burst

  7. A Voiced Stop: [byt] release burst voicing (closure) voicing (vowel)

  8. Voice Onset Time • Voice Onset Time (VOT) is defined as 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 • 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)

  9. Thai Stops • In stressed onset position, English distinguishes between: • unaspirated and aspirated stops. • Languages like French, Dutch and Spanish distinguish between: • voiced and voiceless unaspirated stops. • Thai splits up the VOT continuum into three parts: • voiced, voiceless unaspirated, voiceless aspirated

  10. Thai Stops

  11. [ba] [pa]

  12. English Stop Contrasts • In onset position: • /p/ is voiceless aspirated • /b/ is voiceless unaspirated • In medial position (between voiced segments): • /p/ is voiceless unaspirated • /b/ is voiced • After /s/, in the same syllable: • only voiceless unaspirated stops (no contrast)

  13. Beak, Peak, Speak

  14. Rabid vs. Rapid

  15. 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 may exhibit different phonetic manifestations • Phonemes vs. Allophones

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

  17. Tree vs. Chree • Check ‘em out in Praat

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

  19. Syllable-Final Spectrograms release burst aspiration

  20. 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.

  21. Voice Quality • Note that there are three primary types of vocal fold vibration: • modal • vocal folds lightly adducted; flow of air causes periodic opening and closing of folds (“trilling”) • breathy • vocal folds slightly apart; flow of air makes folds “wave” in the wind • creaky • vocal folds tensely adducted; low airflow causes irregular, low frequency voicing

  22. breathy [] creaky []

  23. Modal to Creaky [ ]

  24. Voice Quality Movies Source: http://www.ling.mq.edu.au/speech/physiology/movies/fibrescope/index.html

  25. Contrasts • Gujarati contrasts breathy voiced vowels with modal voiced vowels: • Jalapa Mazatec has a three-way contrast between modal, breathy and creaky voiced vowels:

  26. Voiced Aspirated • Some languages distinguish between (breathy) voiced aspirated and voiceless aspirated stops and affricates. • Check out Hindi:

  27. [phal]

More Related