Speech Production

Question 1

What is articulation?

Answer 1

A change in vocal tract shape. When you produce a sound, position tongue, lips, jaws differently so the vocal tract produces different sounds

Question 2

What does modulation of the oropharynx change?

Answer 2

Formant frequency patterns

Question 3

What is speech?

Answer 3

A series of syllables - building blocks of words

Question 4

What are syllables

Answer 4

Consonant plus vowel. speech = CVCVCVCV

Question 5

What are vowels characterised by?

Answer 5

an open configuration of the vocal tract so that there is no build up of air pressure above the glottis

Question 6

What are consonants characterised by?

Answer 6

constriction or closure at one or more points along the vocal tract

Question 7

What does the human supra laryngeal vocal tract consist of?

Answer 7

Alveolar ridge
Tongue lip, blade and body
Larynx
Hard palate
Soft palate
Uvula
Pharynx
Tongue root
Epiglottis - closes the larynx when you swallow

Question 8

How to perceive vowels?

Answer 8

Different vowels have different distributions of energy among the formants - different peaks excite different areas in the basilar membrane

Question 9

Why is the ear important?

Answer 9

It is a sound analyser which can detect formant frequencies by the different amounts of excitation at different places along the basilar membrane

Question 10

Why are consonants important?

Answer 10

The place and the manner of articulation - where and how they are produced

Question 11

Place of articulation

Answer 11

Bilabial - lips
Labio-dental - lips and teeth
Alveolar - tongue and alveolar ridge
Palatal - tongue and hard palate
Velar - tongue and velum

Question 12

Manner of articulation

Answer 12

Different vibrations occur at different points, producing different consonants
stop: involve interruption of air flow and vibration inside the larynx
nasal - involve vibration inside nasal cavity
fricative, approximate and affricate - involve secondary vibration in contact with articulators

Question 13

What are the types of consonants?

Answer 13

Voiced or voiceless
voiceless - long interruption of vibration (t, p, k, sound different)
voiced - continuous (sound the same)

Question 14

Is speech a series of discrete syllables?

Answer 14

No, we can’t segment speech

we can’t cut and paste the phonetic elements of speech to make words and sentences

Question 15

Frequency resolution problem

Answer 15

Speech contains 20 to 30 meaningful sound segments/second

but we can only identify 7-9 segments/second and we hear a tone above 20 segments/second

Question 16

Why is speech a continuous phenomenon?

Answer 16

There are no gaps between words
Can’t see where the words are stopped and starting - as we speak, there is a smooth change from one speech sound to the next

Question 17

What causes us to hear the consonants w and g?

Answer 17

The formant transitions = changing formant pattern at the start of each syllable

Question 18

What is co-articulation?

Answer 18

The articulation of two or more speech sounds together, so that one influences the other
not one thing responsible for one letter
the articulatory gestures characteristic of each isolated sound are never attained in isolation but melded together in a composite characteristic of the syllable

Question 19

Different transitions - same consonant

Answer 19

Different transitions code d in front of i or a:

dee or da - you can’t paste the formant transition of the d of di with a to generate da

Question 20

Same noise - different consonant

Answer 20

The same noise codes for p in front of i but for k in front of a

Question 21

Why does speech not have invariant acoustic targets?

Answer 21

The acoustic realisation of the consonant changes with the vowel, even only producing the s, you know what is following it because of how you have articulated it
vowel is encoded inside the consonant - this is due to co-articulation

Question 22

Advantages of coarticulation

Answer 22

Information about different segments is spread across time
you know what is coming next because of the type of consonant you have already produce
spreading information across time makes it easier to transmit information at a fast rate

Question 23

Disadvantages of coarticulation

Answer 23

For perception or machine recognition, there are no constant acoustic targets in speech:
the same consonant can be represented as different sounds in different contexts
the same sound can be heard as different consonants in different contexts
lack of invariance