13 - Acoustics 3 - Vowels

Question 1

What is the F1 rule?

Answer 1

The frequency of F1 tends to DECREASE with INCREASES in tongue height

Question 2

What is the F2 rule?

Answer 2

The frequency of F2 tends to DECREASE with BACKWARD tongue positions

Question 3

What is the lip rounding rule?

Answer 3

The frequencies of F1 and F2 (and all other formants) are LOWERED by lip rounding

• recall, this is because a constriction is being created at a place of volume velocity maxima
• also recall that longer tubes have lower resonant frequencies

Question 4

List the 4 corner vowels from highest F1 to lowest F1 value

Answer 4

a (730)
ae (660)
u (300)
i (270)

Question 5

List the 4 corner vowels from highest F2 to lowest F2 value

Answer 5

i (2290)
ae (1720)
a (1090)
u (870)

Question 6

Do high vowels tend to have higher or lower fundamental frequencies?

Answer 6

Higher

Question 7

Do high vowels tend to have higher or lower intensities?

Answer 7

Lower

Question 8

Are vowels longer or shorter before a voiced consonant, compared to a voiceless consonant?

Answer 8

LONGER vowels before VOICED consonants

Question 9

Which are longer: tense vowels (I, a, u) or lax vowels (ae)?

Answer 9

Tense vowels

Question 10

Which vowels are longer: high vowels or low vowels?

Answer 10

Low vowels

Question 11

Which are associated with longer vowels: fricatives or stops?

Answer 11

Fricatives

Question 12

Why are vowels in CV (consonant-vowel) or VC contexts often perceived better than isolated vowels?

Answer 12

Formant transitions

Question 13

What is formant undershoot?

Answer 13

When segmental context or prosodic elements cause the vowel formant frequencies to change

e. g. isolated vowel vs vowel in a sentence
- fast vs slow speech
- stressed vs unstressed context

-vowel steady states may have a more important role as a vehicle for prosodic cues than as a cue for marking vowel identity
(allow time for pitch inflections, stress marking, etc)

Question 14

What are diphthongs?

Answer 14

Vowel-like sounds that are produced with an open vocal tract and a well defined formant structure
-unlike vowels, diphthongs cannot be characterized by static formant values

Question 15

Since diphthongs cannot be characterized by static formant values, what are they defined by?

Answer 15

Defined by a dynamic change in the formant pattern over time

• often defined by their starting and final positions (formant patterns)
• e.g. bough, bye, boat, bay, boy

Question 16

Since the start and final positions of diphthongs can vary quite a lot with context and speech rate, what else might be rely on to identify them?

Answer 16

Rate of formant change (slope value)