Hearing part 3

Question 2

What are the two theories for how we perceive sound?

Answer 2

Place and temporal theories of pitch perception

Question 3

What does the place theory of pitch perception say?

Answer 3

Frequency of sound determines location of greatest movement along basilar membrane –> determines which auditory nerves have peak activity –> determines perceived pitch

Question 4

What is an issue for place theory?

Answer 4

Effect of the missing fundamental

Question 5

Why is the effect of the missing fundamental an issue for place theory?

Answer 5

Pitch is the same despite missing fundamental frequency of 100 Hz

No longer peak activity at a place for 100 Hz but same perceived pitch

Question 6

What is another issue for place theory?

Answer 6

Amplitude modulation

Question 7

What is amplitude modulation?

Answer 7

fluctuating level (amplitude) of sound at specific frequencies

Question 8

How does amplitude modulation have an issue for place theory?

Answer 8

Amplitude modulation changes pitch perception despite same frequencies of sound

Question 9

What does the temporal theory for pitch perception argue?

Answer 9

It doesn’t matter where along the basilar membrane is activated, it depends on the rate it is getting activated

Question 10

What is the temporal theory of pitch perception?

Answer 10

timing or repetition rate of a sound is available even when the fundamental (200 Hz) is missing and with amplitude modulation – solves the issues of the place theory

Question 11

According to the temporal theory of pitch perception, why do the sounds with the missing fundamental sound so similar?

Answer 11

it leads to phase locking still at 200 Hz because repetition is the same

Question 12

What does the place theory of pitch perception depend on?

Answer 12

which auditory nerves are active - place along basilar membrane

Question 13

What does the temporal theory of pitch perception depend on?

Answer 13

timing of when auditory nerves are active
Temporal pattern of activation

Question 14

What is most important for pitch perception?

Answer 14

likely both location and timing of activation matters

Question 15

What is the acronym for remembering the auditory pathway?

Answer 15

SONIC MG

Question 16

What are the steps in the auditory pathway? Say where those nuclei are located?

Answer 16

Auditory nerve
Cochlear nuclei (medulla)
Superior olivary nucleus (pons)
Inferior colliculus (midbrain)
Medial Geniculate nucleus (thalamus)
Primary auditory cortex

Question 17

What are the three parts of auditory cortex?

Answer 17

Core, belt, parabelt

Question 18

Where is the primary auditory receiving area located? (what lobe)

Answer 18

temporal lobe

Question 19

What is the core?

Answer 19

A1/ primary auditory cortex

Question 20

What does the belt surround?

Answer 20

the core

Question 21

Is the tonotopic map also represented in A1?

Answer 21

Yes

Question 22

What is a tonotopic map?

Answer 22

arrangement based on length of cochlea from low to high frequency

Question 23

Does the tonotopic mapping get repeated past primary auditory cortex?

Answer 23

yes

Question 24

Where are pitch neurons located?

Answer 24

in primary auditory cortex

Question 25

What did the study on pitch neurons in auditory cortex of marmoset monkeys do?

Answer 25

recorded from a single neuron and played different groups of harmonics of the fundamental frequency - each composition has the same repetition rate (at the missing fundamental)

Question 26

What did the study on pitch neurons find?

Answer 26

neuron responds to groups of harmonics that present the same pitch (182 Hz) - pitch neurons respond to subjective perception of sound

Question 27

What effect did the study on pitch neurons demonstrate?

Answer 27

the effect of the missing fundamental

Question 28

What happened when they played a pure tone to the pitch neuron? (2 things it showed)

Answer 28

frequency selective (182 Hz/ fundamental frequency) does not respond to individual harmonics (only groups) - only responds alone to the fundamental frequency --> need repetition at fundamental

Question 29

What do pitch neurons respond to overall?

Answer 29

subjective perception of pitch

Question 30

What else did the study on pitch neurons do?

Answer 30

Mapped out where pitch neurons are found

Question 31

What do the large and small dots represent?

Answer 31

Small dots represent neurons that only respond to pure tones at characteristic frequencies (basic) Large dots represent neurons responding to pitch of complex tones with missing fundamental (more subjective perception)

Question 32

What is our subjective interpretation of sound frequency?

Answer 32

pitch

Question 33

What are cochlear implants used for? What is still intact?

Answer 33

address hearing loss due to damaged or nonworking hair cells auditory nerve still intact

Question 34

How many people have cochlear implants?

Answer 34

300000

Question 35

What happens with language skills from cochlear implants?

Answer 35

majority of deaf children who receive cochlear implants before 18 months of age had language skills similar to their hearing peers

Question 36

What are the three external components of cochlear implants?

Answer 36

Microphone Processor Transmitter

Question 37

What are the two internal components of cochlear implants?

Answer 37

Receiver and electrodes

Question 38

What does the microphone do?

Answer 38

Transduces sounds into electricity

Question 39

What does the processor do?

Answer 39

Analyzes sound into frequency bands

Question 40

What does the processor simulate?

Answer 40

Simulates place specific activation of basilar membrane --> like cochlea

Question 41

What does the transmitter do?

Answer 41

sends signals and power to internal implant

Question 42

What does the receiver do?

Answer 42

Receives signals and power and transmits to electrodes

Question 43

What do the electrodes do?

Answer 43

Stimulate different auditory nerves along length of cochlea

Question 44

Where does the electrode array go?

Answer 44

implanted into the cochlea

Question 45

What is the issue with the implantation of the cochlear implant?

Answer 45

doesn't make it to the apex - can't activate those locations

Question 46

What would a spectogram look like for cochlear implants?

Answer 46

low frequencies missing

Question 47

What are the three types of concerns about the cochlear implant?

Answer 47

ableist concerns, cultural concerns, developmental concerns

Question 48

What are the ableist concerns of cochlear implants?

Answer 48

Cochlear implants imply that deafness is a medical disability that should be cured

Question 49

What are the cultural concerns of cochlear implants?

Answer 49

reduces the number of ASL speakers

Question 50

What are the developmental concerns of cochlear implants?

Answer 50

brain must learn to interpret the signal as language - this process can be difficult and may lead to impaired language abilities compared to ASL