lecture 7 - human speech perception and comprehension

Question 1

speech is variable

Answer 1

Every word takes on a different acoustic shape each time it is uttered. Due to -

Speaker – vocal track size, regional accent, socioeconomical tier.

Articulation rate – 4/5 syllables/ sec in sentences.

Prosody – the music of speech – rhythm, melody, amplitude.

Mode – voiced, whispered etc..

Coarticulation – individual phonemes influenced by preceding/ upcoming segments,

Question 2

ways of visualizing sound

Answer 2

1. the wave form

2. the spetrogram

Question 3

speech is quasi-contimuous

Answer 3

Speech has no unique/systematic way to flag word boundaries

There is rarely silence between two words.

Question 4

speech is lexically ambiguous

Answer 4

Words are made out of a limited number of sounds and syllables. Therefore, embedded words are everywhere, inside other words.

Ambiguity also arises due to straddling words, as soon as we put two words together.

Question 5

speech is audiovisual

Answer 5

Visual information is given by the lips and adjacent areas of the face about articulation is integral to speech perception, when available.

Question 6

Q1. What kind of information does the listener need for identifying words?

Answer 6

1 - phonemes

2 - supra-phonemic information

Question 7

phonemes

Answer 7

Building blocks of vocab.

Smallest units in the signal allowing meaning distinction.

In limited number, hence words are created by combining them in an unlimited number of ways, specific to the language.

English has 20 vowels and 24 consonants.

Question 8

supra-phonemic information

Answer 8

This is the prosody/ music of speech - I.e. rhythm, melody and energy.

Lexical stress/ accentuation

Tones

Question 9

How is speech mapped onto the words we know?

Answer 9

1. directionality of lexical access.
2. active competition between words.
3. interactivity from memory to perception, and back.

The ‘Ganong’ effect 1980 -

Question 10

the ‘ganong’ effect

Answer 10

1980 - An ambiguous constant (‘k/g’) is perceived in accordance with the lexical context: more as g before – IFT, but more as k before – ISS

Question 11

How do we segment the speech stream into words?

Answer 11

lexical solutions

prelexical cues

Question 12

lexical solutions

Answer 12

1. word offset anticipation

2. lateral inhibition between word memories

Question 13

prelexical cues

Answer 13

1. allophonic cues
2. rhythmic cues
3. phonotactic cues