Vowels

Question 1

What are vowels?

Answer 1

Vowels are sounds pronounced with an open vocal tract, associated with a steady state articulatory configuration and a steady state acoustic pattern

Question 2

Give examples of the 12 monophthongs in English

Answer 2

There are 12 monophthongs in English (i,ɪ,e,æ,ɑ,ɒ,ɔ,ʊ,u,ʌ,ɜ,ə). There are however many more used in other languages.

Question 3

How are vowels characterised?

Answer 3

with a simple set of acoustic descriptors (the frequencies of the first three formants)

•. A single vowel can be represented as a single point in a 3 dimensional space defined by F1,F2 and F3

Question 4

What does it mean by vowels having ‘steady state’

Answer 4

They have a steady state articulatory configuration and steady state acoustic pattern

Question 5

How did Lehiste and Peterson find that vowels differ from one another?

Answer 5

1. Have inherent differences in duration (long /tense vowels have greater durations than short or lax vowels. Open jaw vowels (low /open vowels) are longer than the close jaw vowels (high or close vowels)
2. Vowels are produced in context with other sounds , they differ in their formant trajectories : tense vowels have short vowel to consonant transitions and long steady states whilst lax vowels have proportionately long offglides and short steady states.

Question 6

How are formant frequencies related to vowels?

Answer 6

These are the primary cue for vowel perception. The difference between vowel sounds are independent of the larynx. The primary acoustic characteristic of vowels is the location of the formant frequencies, specifically, the first three formants.

Question 7

What is the F1-F2 chart?

Answer 7

the most widely used and best known acoustic description of a class of speech sounds.

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•Many English vowels can be distinguished from the first two formants alone.

Question 8

What are the two rules related to constrictions and F1?

Answer 8

Oral constrictions and pharyngeal constrictions

Question 9

what happens in an oral constriction relating to F1?

Answer 9

1. F1 frequency lowered by constriction in the front half of the oral part of the vocal tract , the greater constriction the more F1 is lowered. (e.g open for [a] but closed for [i]

Question 10

what happens in a pharyngeal constriction relating to F1?

Answer 10

1.he frequency of F1 is raised by constriction of the pharynx and the greater the constriction the more F1 is raised. E.g least constricted =[o] but most constricted = [a as in part]

Question 11

What are the two rules relating to F2?

Answer 11

Back tongue constriction and front tongue constriction

Question 12

What happens in a back tongue restriction with regards to the F2?

Answer 12

• The frequency of F2 is lowered by a back tongue constriction and greater the constriction the more F2 is lowered. E.g back vowel [u] as a lower frequency (about 800 hz) whilst the neutral vowel is 1500 hz
• [o] has less lip rounding and so less constriction- therefore higher frequency for [o] than [u] (around 900 hz)

Question 13

What happens in Front tongue constriction regarding F2?

Answer 13

• the frequency of F2 is raised by a front tongue constriction [E] vs [i] = rise in F2

•Go in order from the least tongue constriction (ae) to the greatest for (i)
ie. ae, E, e, i

Question 14

What does the effect of lip rounding have on the formants?

Answer 14

• The frequencies of all formants are lowered by lip-rounding
• The more the rounding the more the constrictions and the more the formants are lowards.
• Lip-rounding plays an important part in the back vowels and involves a series of lip positions
• Goes from [a] , [or] [o] and [u]

Question 15

What did Pickett find with regards to noise effects on the perception of vowels?

Answer 15

• In noisy situations the second formant is apparently compromised more than the first formant - therefore easily confusable vowels are more likely to be ones that share similar F1 characteristics (e.g i and u , e and o and E and or , a and ah ) the front vowels and the back vowels therefore correspond.

Question 16

What acoustic features do low vowels possess?

Answer 16

greater in intensity, duration, F1 frequency, and the F1-F0 difference.

Question 17

What acoustic features do high vowels possess?

Answer 17

greater in the F0 but lower in intensity, duration F1 frequency and F1-F0 difference

Question 18

What acoustic features do front vowels possess?

Answer 18

greater in F2 frequency, F2-F1 difference

but smaller F3-F2 difference

Question 19

What acoustic features do back vowels possess?

Answer 19

Greater F3-F2 difference, smaller F2 frequency, smaller F2-F1 difference

Question 20

How does duration vary in different vowels?

Answer 20

Duration = tense vowels have a longer duration than lax vowels

Question 21

Which vowels are more centralised, tense or lax vowels?

Answer 21

lax vowels are more centralized than tense vowels

Question 22

The sum of F1 , F2 and F3 are greater in rounded or unrounded vowels?

Answer 22

unrounded vowels

Question 23

Describe how the formant values differ in [I] and [ah] Vowels

Answer 23

• [i] = F1 240 hz, F2 2450 hz, F3 3,200 Hz

* [ah] = F1=810 hz, F2 1,250 hz, F3= 2,400 Hz

Question 24

Explain how vowels differ in their durations?

Answer 24

Vowels can differ substantially in their durations.

Vowels can be defined as tense vowels or lax vowels.

Tense vowels /i, u, ɔ, ɜ etc. /have greater duration than lax vowels /I, ʊ ,ɒ, æ etc. /

Effect of vowel duration is more important for the vowel group /,ɑ, ɔ, ^/ and the pair ae and E/

Vowels produced with a relatively low jaw position are longer than vowels produced with a relatively close jaw position.

•Lip rounding can affect the lengthening of the vocal tract, which causes all formants to assume lower frequencies than for a non rounded configuration.

Question 25

How does the F1 change in Front vowels as they go from Closed to open?

Answer 25

it increases! | [i] =237, [e] =449 [E]= 544 [ae] =654

Question 26

How does the F1 change in Back vowel as they go from open to closed?

Answer 26

it decreases! | [ah]=712 [or] = 627 [o]=472 [u]=333

Question 27

How does the F2 change in Front vowels as they go from closed to open?

Answer 27

it decreases! | [i]= 2226 , [e]=2077 , [E] =1773, [ae] 1731]

Question 28

How does the F2 change in Back vowels as they go from closed to open?

Answer 28

stays relatively the same.

Question 29

What are the Formant frequencies of a neutral vowel e.g [3]

Answer 29

F3 (~ 2326 Hz) F2 (~ 1379 Hz) F1 (~ 480 Hz)

Question 30

Explain the formant trajectories of tense vowels and lax vowels?

Answer 30

* Tense vowels -have proportionally short offglides and long steady-state. * Lax vowels -have longer of glides and a short steady-state.

Question 31

Explain the different F0 patterns of vowels?

Answer 31

* High vowel = higher fundamental frequency than low vowels. * It is doubtful that fundamental frequency differences in vowels play a major role in vowel recognition,but they may be secondary ces and ca be exaggerated by some speakers to be more salient Vowels are produced with a relatively open vocal tract and the airstream is not severely impeded. The resulting acoustic signal is therefore relatively loud. Vowels are usually produced with vocal fold vibration.

Question 32

how are vowels affected by bandwidth and Amplitude?

Answer 32

Each formant of the vowel tract during production has a bandwidth. Formant bandwidths generally increase with formant number, so higher formants have larger bandwidths than F1. However, experiments have shown the bandwidth has very little effect on perception of vowel!! Formant amplitude is related to bandwidth. The relative amplitudes in formants in a vowel are determined by their formant frequency, the bandwidths of the formants and the energy available from the source.

Question 33

What is the length rule? how does it effect F3?

Answer 33

* the average frequencies of the vowel formants are inversely proportional to the length of the pharyngeal-oral tract. In other words, the longer the tract, the lower its average formant frequencies. * The pharyngeal-oral tract of an infant is half that of a man- therefore following the length rule , would be at frequency locations will be twice those of a man. In general- the location and spacing of formant F3 are more closely correlated with length of vocal tract than for F1 and F2.

Question 34

How do Nasalised vowels compare to their non nasal counterparts?

Answer 34

* Larger formant bandwidths * Less intensity * Higher frequency F1 * Lower F2 and F3