2.5 - Speech Perception

Question 1

Speech Stimulus

Answer 1

Articulary Gestures (physical movement of muscles to create sound)

Question 2

Vocal Chords

Answer 2

Muscles where speech production occurs (Vibrating = voice, non-vibrating = voiceless)

Question 3

Speech Spectrogram

Answer 3

graph of speech sounds by Frequency (Hz) per second. Contains formants and formant transitions

Phonetic Segments overlap

Question 4

Formant

Answer 4

On Speech Spectrogram: Energy clusters in complex sounds

Question 5

Formant Transition

Answer 5

Where it slops in or out of a formant, crucial in specific sounds (ex: Bah vs Pah)

Question 6

Coarticulation

Answer 6

Phonemes sounds can change depending on what precedes or follows it (Same sound, different speech spectrograph based off of before and after)

Question 7

Facts about speech production

Answer 7

specific words are not produced the same way for specific individuals, no single constant pronunciation exists for phonemes

Question 8

Production of Vowels

Answer 8

Tongue Only

Question 9

Production of Consonants

Answer 9

Place of articulation (whats touching) and manner of articulation (how it is touching)

Question 10

Parts of mouth involved in production of consonants

Answer 10

Lips, Teeth, Tongue, Alveolar Ridge, Palate, Velum, Glottal

Question 11

Voicing

Answer 11

(voice vs voiceless) the delay between passage of air and when vocal cords vibrate (onset is around 10ms) and is the difference between hearing Pah vs Bah

Question 12

VOT

Answer 12

Voicing onset time: 10-20mS (where it changes)

Question 13

Phonetic boundary

Answer 13

where voicing onset time occurs (changes sound)

Question 14

Special Mechanism Theory of Speech Perception

Answer 14

(Inborn belief) Speech depends on specific mechanisms (different than other acoustic information)

Example: Motor theory

Question 15

Motor Theory of Speech Perception

Answer 15

(special mechanism camp)
Speech perception is the result of activation of motor program required to produce a phoneme
IE: to understand speech you need to know the articulary gestures (If you haven’t heard a sound, you can’t produce it)

Question 16

General Mechanism Theory of Speech Perception

Answer 16

(Learnt belief) no special speech module exists, produced same as non-speech sounds

Not a theory but rather same theories as regular sound perception theories (cues for sound localization and sound distinction)

Question 17

Evidence of General Mechanism Camp

Answer 17

Variation in the same language but can still understand each other

Question 18

Segmentation

Answer 18

Breaking down quality (Fundamental and harmonics) of words (this is done before 1 years old) afterwards then word recognition processes develop and takes over

Question 19

Categorical Perception

Answer 19

Suggests that we prefer discrete units as opposed to gradiations in acoustic properties

Needs: 
High discriminability (sharp identification of speech sounds on a continuum) 
Low discriminability (within phonetic categoies) 

evidence:
EX: BAH vs PAH
You can identify when phonetic boundary but within the category no discrimination
at the VOT there is low discrimination

evidence against:
animals without speech have categorical perception (example: chinchillas)
non-speech sounds produce categorical perception

How to measure:
- oddity method

in the end:
evidence against because its too contradicting

Question 20

Oddity method

Answer 20

3 stimulus, 2 are the same. pick out which one is the odd one out

Question 21

Linguistic Features Detector

Answer 21

specific detection mechanism for linguistic features.

adaptation of a heard sounds fatigues said detector for when we hear another sound

Question 22

Duplex Detection

Answer 22

Same sound can be heard as speech or not speech

• categorical perception only occurs when speech is perceived, then speech is special

experiment:
- present pieces of a sound (base in one ear and transition in the other)
- people who haven’t heard the speech sound will perceive it as pieces
- people who have heard the speech sound will perceive it as a whole

proves speech is special

Question 23

Laterialization of Language

Answer 23

left hemisphere of brain is presumed to process speech
there is a right ear advantage in people that are right handers

experiment:
- dichotic presentation of verbal stimuli
0 if it produces a left hemisphere advantage (right ear) then speech is special

speech is special

however:
- doesn’t work for left handers
advantage is not obtained fo vowels

Question 24

localization of language

Answer 24

strongest evidence that speech is special

there are special areas of the brain involved in speech in the left hemisphere (brocas area and wernickes area)

Question 25

Brocas Area

Answer 25

responsible for language production

Aphasia:
- person can understand language but words are not properly formed (Slowed and slurred)

Question 26

Werenicks Area

Answer 26

responsible for language production and comprehension

Aphasia:

• loss of ability to understand language
• speaks clearly but doesnt make sense (word salad)

Question 27

Audiovisual integration

Answer 27

2 types of sensory information voice (auditory) and gestures (visual)

evidence: mcgurk effect

arguable??

Question 28

mcgurk effect

Answer 28

movement clues influence speech perception (speech perception is automatic )

Question 29

Is speech special>

Answer 29

Kind of
strong evidence: duplex detection and localization

contradictory data: categorical perception and linguistic feature detectors and lateralization of speech

arguable: audiovisual integration