1. Vowel production Introduction to sound waves
Phonetics COMD2338 Taylor
Vowel production
Introduction to sound waves

2. How many vowel sounds are there in US English?
Between 11 and 13, depending on your dialect
Does not include diphthongs
Ex: Beat, bit, bait, bet, bat, but, bother, boot, book, boat, bawdy, body

3. Describing vowels Difficult to use tongue position as a descriptor
High-low/front-back should not be viewed as absolute descriptions of tongue positions
Vowel chart reflects frequencies; i.e., how one vowel sounds relative to the others
No distinct boundaries between vowels

4. http://www.uiowa.edu/~acadtech/phonetics/ [u] [i] [ʌ] [o] [æ] [ɑ]
point out differences here
[æ]
[ɑ] 4

5. Sound waves: Why describe sounds in terms of their physical nature?
Helps speech pathologists understand how sounds can be confused
For vowels, in particular, articulatory gestures are not very good descriptions
Recordings
Speech synthesis 5

6. What is sound?
Sound: a disturbance of (air) molecules by some kind of movement
These disturbances are called sound waves
Sound waves cause molecules to move back and forth, bumping into one another
Eventually this disturbance travels to your ear, causing your ear drum to vibrate
Your brain perceives this as sound
We tend to think of sound as something produced by our voices or by an instrument or something else. But a good way to understand that sound is produced by a disturbance of air molecules is to wave your hand back and forth beside your ear. You can hear (and feel) the disturbance in the air. 6

7. How do sound waves work? Sound waves can differ in
pitch
quality
loudness
They spread like ripples in a pond. . .
Voiced sounds: large, regular pulses
Voiceless sounds: smaller, irregular pulses 7

8. Speech sounds
Speech sounds are created when a sound passes through the vocal tract
This sound resonates at different frequencies
The frequencies at which this sound resonates are called formants
Linguists have two ways to visually represent speech sounds: waveforms and spectrograms 8

9. Terminology Frequency: how fast the sound wave travels
Measured in terms of Hertz (cycles per second)
Think in terms of pitch
Amplitude: how big of a disturbance the wave makes
Measured in terms of decibels
Think in terms of loudness 9

10. Sound properties of vowels
Complex acoustic structure
Number of different frequencies simultaneously
pitch (auditory property)
fundamental frequency (acoustic measure)
pulses/second: 100Hz = 100 pulses/second
you can hear F0 by using creaky voice
added frequencies from resonance
you can hear these by whispering/whistling

11. Spectrograms
A spectrogram is an illustration of time, frequency, and amplitude
Time: horizontal axis
Frequency: vertical axis
Amplitude: how dark the bars are
Each dark bar represents a vowel formant 11

12. How to describe English vowel sounds
Parameters (in order)
Height
Frontness
Rounding
Tenseness (if applicable)
Diphthongs
Dialect issues

13. All vowels (canonical)

14. AmEngl Vowel Chart (Canonical Placement)
beat [i]
boot [u]
bit [ɪ]
father [ɚ]
book [ʊ]
bait [e]
sofa [ə]
boat [o]
bet [ɛ]
but [ʌ]
caught [ɔ]
bat [æ]
father [a]
cot [ɑ]
Beware: There is considerable variation in English.

15. Some vowel mnemonics English height (descending):
front: 'green mints may melt fast'
back: 'nude cooks wrote bawdy logs'
English lip rounding:
green vs nude
mint vs cook
may vs wrote
melt vs bawdy

16. Central Vowels in English
[ə] and [ʌ] are both considered “mid central unrounded vowels”, and the tense/lax distinction is not applicable.
[ʌ] is used in stressed syllables and stressed one-syllable words:
cup, rug, above
[ə] is used in unstressed syllables, unstressed one-syllable words like ‘the’ [ðə]:
sofa, above, the house
Use [ɚ] for unstressed syllables ending in [ɹ]:
father 16

17. Moving from one V to another
Involves changing the auditory quality of the vowel
accomplished by moving the tongue and changing the shape of the chamber
difficult to describe exactly how your tongue is moving
may not move the same way twice
does not move the same way in different contexts

18. Diphthongs
The nucleus is usually (although not always) the first V of the pair
[oʊ], [aʊ], [aɪ], [eɪ], [ɔɪ]
The nucleus is more prominent than the off-glide or the on-glide
Off/on-glide is often very short
Exception: [ju] in English
Sometimes transcribed as a glide (consonant)

19. Diphthongs
A diphthong is a combination of vowels. The tongue moves from one vowel position (i.e. “target”) to another.
The final segment of a diphthong is often written as an ‘off-glide’ approximant
English diphthongs:
[aɪ] or [aj] pie, rye, lied
[aʊ] or [aw] cow, how, round
[ɔɪ] or [ɔj] boy, coin, boil
[oʊ] or [ow] cold
[eɪ] or [ej] say
(also: [ij], [uw]) keel, mood
Decide exactly how to write these (and low vowel a) and make sure it matches on handout and on here; Ended here 1/22/09 19

20. American English diphthongs
[eɪ] ‘bait’, ‘gate’
[aɪ] ‘bite’, ‘kite’
[oʊ] ‘boat’, ‘goat’
[ɔɪ] ‘boy’, ‘coy’
[aʊ] ‘pow’, ‘cow’
[ju] ‘cute’, ‘use’
[uw] ‘boo’
[ij] ‘key’

21. Regional dialects: some examples
‘cot/caught’
final [ɚ] to [ə]; [aɹ] to [a]; [ɔɹ] to [ɔ]
[aɪ] to [a] (monophthongization) ‘guy’
[i]–[ɪ] rotation ‘beat’ ‘bit’
[æ] to [iə] ‘candle’