Airstream Mechanisms + Trills

1. Airstream Mechanisms + Trills October 7, 2013

2. Announcements and Such • Next transcription homework is due on Wednesday. • I’m in the midst of grading Production Exercise #1. • You should hear something about it by tonight. • Production Exercise #2 (on place of articulation and airstream mechanisms) will be posted after you get comments back on Production Exercise #1. • By the way, let’s check out an old episode of “The Simpsons”… • 5. We should also check out Miriam Makeba’s “Click Song”.

3. Click Examples • Clicks can be made at five different places of articulation. • Languages which use clicks as contrastive sounds are exclusively found in southern and central Africa. • Particularly in the Khoisan languages

4. !Xoo Examples • !Xoo (spoken in Botswana) contrasts clicks at all five places of articulation • Note that !Xoo is also a tone language. • By convention, a [k] appears before all click sounds, to represent the velar closure.

5. Click Places

6. Click Cues • All clicks are very high in acoustic intensity • i.e., loud • Alveolar and palatal clicks have a transient (short) release • Dental and bilabial clicks have an affricated release • Lateral clicks are somewhere in between

7. Clicks in connected speech • If you listen to clicks as they are produced in a long sequence of connected speech, you may experience a phenomenon known as perceptual streaming. • Sound file source: http://www.rdg.ac.uk/%7Ellsroach/fue/

8. Deep Thought Questions • #1: Is it possible to make a voiced click? • Yes. • #2: Is it possible to make an aspirated click? • Sort of. • #3: Is it possible to make a nasal click? • Yes. • #4: Is it possible to make an ejective click? • Sort of. • Accompanying articulations may be made in conjunction with the click’s velar closure.

9. Zulu Clicks • Zulu is spoken in South Africa.

10. Zhu|hoasi Clicks • Zhu|hoasi is spoken in Namibia and Botswana.

11. Airstream Summary Airflow Pulmonic Glottalic Velaric OUT fricatives, ejectives unattested (egressive) vowels, stops, etc. IN (Tsou) implosives clicks (ingressive)

12. Back to Aerodynamics • Aerodynamic method #1: Stops • start air flow • Remember: Boyle’s Law • And: Air flows from high to low pressure • stop air flow • Just bring two articulators together. • release air flow • Just relax! • Not an explosion • Air pressure differences do the work • Release burst example: Bengali exercises

13. Another Aerodynamic Method • What kind of sound is this? • A Trill. A Bilabial Trill: • Examples from Kele and Titan • (Island of Manus, north of New Guinea)

14. How Fast? • Any volunteers? • Take a look at the waveform • (Note: period vs. frequency) • Do we close and relax our lips each time we do this? • No? • When air blows the lips apart, why don’t they stay apart?

15. Bernoulli Effect • In a flowing stream of particles: • the pressure exerted by the particles is inversely proportional to their velocity • Pressure = constant • velocity • P = k / v •  the higher the velocity, the lower the pressure •  the lower the velocity, the higher the pressure Daniel Bernoulli (1700-1782)

16. Bernoulli Examples • Airplane wing • Frisbee • Shower Curtain • Pieces of paper • Bilabial trills!

17. A Trilling Schematic • Lips are closed • adducted = brought together • Fad = adductive force Fad upper lip outside of mouth inside of mouth lower lip Fad

18. Trilling: Stage 1 • Pressure builds up inside mouth from compression of lungs • Pin = Air Pressure inside mouth • Outside pressure remains constant • Pout = Air Pressure outside mouth Fad Pout = k Pin Fad

19. Trilling: Stage 1 • Pressure differential between inside and outside builds up • This exerts force against the lips P = (Pin - Pout ) Fad Pout = k Pin Fad

20. Trilling: Stage 2 • Pressure differential blows open lips • Air rushes from high to low pressure Fad Pout = k Pin air Fad

21. Trilling: Stage 2 • The opening of the lips means: • P decreases slightly • High velocity of air flowing between lips • Air pressure decreases between lips (Bernoulli Effect) Fad Pout = k Pin Pbl Fad

22. Trilling: Stage 3 • Lips get sucked back together Fad Pout = k Pin Fad

23. Trilling: Back to Stage 1 • If air is still flowing out of lungs, pressure will rise again within mouth • Process will repeat itself as long as air is pushed up from lungs and lips are held lightly against each other Fad Pout = k Pin Fad

24. Trilling: Back to Stage 1 • Air rushes through the lips in a series of short, regular bursts Fad Pin Fad

25. Other Trills • Alveolar trills: [r] • Examples from Kele and Titan • Uvular trills: • Pour example: Edith Piaf • Any other places of articulation for trills?

26. Voicing = Glottal Trills • Voicing occurs when: • air rushes up from the lungs • the vocal folds are brought together (adducted)

27. Creaky Voicing • The flow of air from the lungs forces the vocal folds to open and close. • The slowest type of voicing is called “creaky voice.”

28. Modal Voice • This is normal, or “modal” voicing. The rate of glottal trilling is considerably faster. • How fast do you think the vocal folds open and close in normal voicing?

29. Vocal Fold Specs • In bilabial trills, lips open and close 25 times a second • In modal voicing, the glottal trill cycle recurs, on average: • 120 times a second for men • 220 times a second for women • 300+ times a second for children