L5 - Voice and Speech Processing

Question 1

Mcleer et al 2014: (voice perception study)

Answer 1

• Ps rated social traits on ‘hello’ spoken by 64 people
• listen to hello and rate on 10 different traits
• if voices convey no info, ratings would be random
• but CONBACH ALPHA rating - suggests that people CONSISTENTLY AGREE on whether a voice sounds attractive or confident
• we seem to associate voices with social traits on a collective level

Question 2

many social traits are related and can be mapped to two principle components:

Answer 2

in both genders:
1. the 1st principle component is highly correlated with TRUSTWORTHINESS

2. the 2nd principle component is highly correlated with DOMINANCE.

Question 3

how are voices transmitted?

Answer 3

transmitted via vibrations of the air

Question 4

three main parameters of the voice

Answer 4

• pitch
• intensity
• tempo

Question 5

different cultures?

Answer 5

different cultures may struggle to determine emotion in voice when from very different language.

e.g. Indonesian struggle with German

Question 6

area of the brain processing voices?

Answer 6

temporal voice area (TVA)

Question 7

Belin et al 2000

Answer 7

found that when P listens to voices versus non-vocal sounds there was greater bilateral activity in the temporal cortices

• evidence that we possess specific brain regions for voice processing

Question 8

neural adaptation

Answer 8

a gradual decrease over time in the responsiveness of the sensory system to a constant stimulus

Question 9

speaker identity and vocal emotion?

Answer 9

processed in different regions of the TVA

Question 10

speech processing - top down?

Answer 10

speech is a continuous signal that doesn’t have punctuation or space - how does the brain extract this?

the brain determines what we see/hear and how we perceive follows one of two processing methods.

• our brain extracts LINGUISTIC UNITS of speech such as syllables and changes in tone

Question 11

cocktail party problem

Answer 11

• once the brain knows what to look for in disordered speech - it cannot unhear it (top-down)
• this is why you can hear someone speaking in a club - visually attended

Question 12

what side of the brain is more responsible for speech?

Answer 12

left

speech is left lateralised

• evidence of this comes from neuropschyology - BROCAS and WERNICKES

Question 13

Wernickes

Answer 13

• patient cant understand speech

Question 14

Brocas

Answer 14

• patient cannot produce speech

Question 15

left temporal regions

Answer 15

more specialised in processing time information

Question 16

right temporal regions

Answer 16

more specialised in processing spectral information

Question 17

acoustic information (music)

Answer 17

• musical
• pitch more important
• therefore SPECTRAL info MORE important than TEMPORAL info

Question 18

speech - temporal or spectral?

Answer 18

more important to have TEMPORAL then SPECTRAL information

• as matters more regarding timing rather then gender

Question 19

the acoustic uncertainty principle

Answer 19

you need time to get the frequency correct.

the principle is that there is a trade-off between time and frequency:

• as that - the upper limit of resolution, increasing time resolution can only be achieved at the expense of frequency (spectral) resolution and vice versa

Question 20

the McGurk Effect

Answer 20

• voice saying ‘ba ba’

is heard as: ‘ba ba’ ‘da da’ or ‘va va’
- depending what you are perceiving at the time by looking at mouth movement

Question 21

motor theory of speech perception

Answer 21

• the auditory signal is matched on to motor representations for producing ones own speech rather than matching to an acoustic template

Question 22

neural oscillations for speech segmentation

Answer 22

• may be modulated by the motor system
• facilitates the segmentation of speech signal
• optimal oscillations = 4.5Hz which reflects average syllable rate across human languages

Question 23

why does the McGurk effect arise ?

Answer 23

• one theory could be there is a multi-sensory perception of speech - with involvement of the left superior temporal region
• another theory is that of motor system activation - involving the inferior frontal cortex/premotor regions

Question 24

alpha oscillations?

Answer 24

linked to suppression of irrelevant information

Question 25

speech is processed in a network

Answer 25

dorsal ‘how’

ventral ‘what’

Question 26

auditory-motor connectivity

Answer 26

• McGurk Illusion

- Neural oscillations

Question 27

superior temporal sulcus is specialised for…

Answer 27

processing voice over nonvocal words