1. Laterals + Nasals
November 24, 2008

2. Administrative Stuff Wednesday: quiz! Then: Voice Onset Time (VOT)
Friday: Transcription Exercise
On VOT contrasts in Thai and Bengali
For next Wednesday: the final production exercise
Fricatives, stops and VOT in:
Thai, Quechua, Armenian, Ewe, Toda, Greek and Hebrew.

3. Where were we?
The IPA includes symbols for lateral approximants at four different places of articulation
Peter says:
There are also two symbols for lateral fricatives.
They are voiceless and voiced alveolars.

4. Lateral Approximant Contrasts
Italian contrasts alveolar and palatal laterals.

5. Retroflex Laterals Toda contrasts dental and retroflex laterals.
Toda is spoken in southern India.
In syllable-final position, Korean laterals are typically retroflex.

6. Other Laterals
Mid-Waghi contrasts dental, alveolar and velar laterals.
Mid-Waghi is spoken in the highlands of New Guinea.
Zulu contrasts alveolar lateral approximants and fricatives.
Zulu is spoken in South Africa.

7. Lateral Acoustics Laterals have resonances like vowels…
but are weaker in intensity.
Mid-Waghi: [alala]

8. [l] vs. [l] and are primarily distinguished by F3 much lower in
Also: [l] usually has lower F2 in English
[ ] [ ]

9. Dark vs. Clear /l/
/l/ often has low F2 in English because it is velarized.
[alala]

10. Dark /l/ vs. /w/ Acoustically, velarized /l/ closely resembles /w/…
or high, back, round vowels.

11. Velarization in English
Different dialects:
[l] is velarized only in syllable-final position.
[l] is velarized everywhere except before front vowels.
[l] is velarized everywhere

12. Velarization in English
Note: velarization of [l] leads to low F1 and low F2.
 closely resembles [o].
Leading to dialect Option 4:
The [l] disappears and the velarization is left behind.
The Columbus, Ohio “[o:]dies” station
Coldplay (Devon accent):

13. Nasals
Nasals are the sonorants with the greatest amount of constriction in the vocal tract.
Nasals are produced with an open velo-pharyngeal port
Flow of air is stopped in the mouth
Air flows freely through the nose
Air pressure does not build up behind stop constriction.
 Voicing is not impeded at the glottis.
Note: the speech ready position
Check out the Ken Stevens X-ray film.

14. Nasal Stops
Note: anywhere you can produce an oral stop, you can also produce a nasal stop.
Check out all the nasals in Yanyuwa:

15. Plus One
You can also get a nasal stop at one place of articulation where oral stops never occur
Labio-dental:
Peter says: [ama]
occurs allophonically in:
English “dumbfounded”, “comfort”, (“Banff”)
Catalan “infermer”; Italian “invece”
Note: flow of air through nose reduces airflow through mouth
vocal tract airflow too weak for frication at the labio-dental closure.

16. Voiceless Nasals Nasalization is disastrous for fricatives.
There are no (uncontroversial) nasal fricatives in the languages of the world.
There are, however, voiceless nasals in a few languages.
Examples from Burmese:

17. Nasal Acoustics The acoustics of nasal stops are quite complex.
Here’s the general pattern of what to look for in a spectrogram for nasals:
Periodic voicing.
Overall amplitude lower than in vowels.
Low frequency first formant.
Higher formants have low intensity.
Formants have broad “bandwidths”.
Let’s account for each of these acoustic characteristics in turn.

18. Decreased Overall Amplitude

19. Damping
The decreased overall amplitude of nasals is due to several factors, including damping.
Recall that resonance occurs when:
a sound wave travels through an object
that sound wave is reflected...
...and reinforced, on a periodic basis
The periodic reinforcement sets up alternating patterns of high and low air pressure
= a standing wave

20. Resonance in a closed tube

21. Damping, schematized In a closed tube:
With only one pressure pulse from the loudspeaker, the wave will eventually dampen and die out
Why?
The walls of the tube absorb some of the acoustic energy, with each reflection of the standing wave.

22. Damping Comparison A heavily damped wave wil die out more quickly...
Than a lightly damped wave:

23. Damping Factors The amount of damping in a tube is a function of:
The volume of the tube
The surface area of the tube
The material of which the tube is made
More volume, more surface area = more damping
Think about the resonant characteristics of:
a Home Depot
a post-modern restaurant
a movie theater
an anechoic chamber

24. An Anechoic Chamber

25. Inside Your Nose In nasals, air flows through the nasal cavities.
The resonating “filter” of nasal sounds therefore has:
increased volume
increased surface area
 increased damping
Damping decreases amplitude…
And spreads energy across a wider range of frequencies.
= increased bandwidth

26. Bandwidth in Spectrograms
F3 of
F3 of [m]
The formants in nasals have increased bandwidth, in comparison to the formants in vowels.

27. Perceiving Nasal Place
Nasal “murmurs” do not provide particularly strong cues to place of articulation.
Can you identify the following as [m], [n] or ?
Repp (1986) found that listeners can only distinguish between [n] and [m] 72% of the time.
Transitions provide important place cues for nasals.
Repp (1986): 95% of nasals identified correctly when presented with the first 10 msec of the following vowel.
Can you identify these nasal + transition combos?
1 = alveolar
2 = bilabial
3 = velar
1 = velar
2 = alveolar
3 = bilabial

28. [l] vs. [n] Laterals are usually more intense than nasals
less volume, less surface area = less damping
 break between vowels and laterals is less clear
[ ] [ n ]

29. Interlude: Voice Quality
I’ve talked about (at least) two different types of vocal fold vibration:
modal
vocal folds lightly adducted; flow of air causes periodic opening and closing of folds (“trilling”)
2. creaky
vocal folds tensely adducted; low airflow causes irregular, low frequency voicing
3. breathy
vocal folds slightly apart; flow of air makes folds “wave” in the wind

30. breathy
[ ]
creaky

31. Modal to Creaky
[ ]

32. Voice Quality Movies
Source:

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

34. Breathy Voiced Nasals
Distinctions between voiced and breathy voiced nasals are also possible.
Examples from Newari (spoken in Nepal):

35. Nasal Plosion One last, random thing about nasals--
It is possible to “release” an oral stop closure by opening up the velo-pharyngeal port.
The release burst caused thereby is referred to as nasal plosion.
Peter says hidden, sadden, sudden, leaden
with nasal plosion
without nasal plosion
Nasal plosion occurs in “pre-stopped” nasals in Russian:
[dno] “bottom” [dna] “of the day”