L6 - Hearing

Question 1

How does the ear detect a sound stiulus?

Answer 1

pressure changes in the ear

Question 2

what is the pathway of the hearing process?

Answer 2

The ear receives sound
brain processes the information

Question 3

how do pressure changes influence hearing?

Answer 3

movements or vibrations of an object cause pressure changes in an elastic medium e.g., air or water

e.g., diaphragm of a speaker moves out, pushing molecules together (condensation) when it moves back it pulls the molecule apart (refraction)

Question 4

How are sound waves created + what are they?

Answer 4

Alternation of condensation (high air pressure) + refraction
(low air pressure)

a sound wave is a variation in air pressure that travels through a medium e.g., water, air etc.

Question 5

what’s amplitude in regards to sound?

Answer 5

the difference in pressure between peaks and troughs of the sound wave

determines the loudness of the sound

Question 6

What is frequency in regards to sound?

Answer 6

The no. of pressure change cycles per second (Hz)

determines the pitch of sound

Question 7

What is the human hearing range?

Answer 7

Frequencies between 20 Hz - 20,000 Hz

Question 8

what is the ecological adaptation regarding frequencies in humans?

Answer 8

Sensitivity to specific frequencies is influenced by ecological needs and the environment.

Question 9

Why do bats + dolphins have echolocation + what is it?

Answer 9

Bats and dolphins have evolved echolocation, using high-frequency clicks for navigation and hunting.

Question 10

What’s the process of signal transduction?

Answer 10

sounds stimulus reaches the receptors in the inner ear

it’s transduced into electrical signals

these signals are processes to determine pitch and loudness

Question 11

What is the outer ear comprised of + what are it’s functions?

Answer 11

Pinna + ear canal

Capturing and funneling sound waves to the eardrum

Question 12

What is the middle ear comprised of + what are it’s functions?

Answer 12

contains the ossicles (malleus, incus, stapes) –> amplifies vibrations

eardrum –> vibrates in response to sound waves

Question 13

What is the inner ear comprised of + what are it’s functions?

Answer 13

the cochlea - filled with liquid + contains the organ of corti

the stapes vibrates against the oval window causing fluid movement

Question 14

what’s the structure of the cochlea

Answer 14

divided into scala vestibuli + scala tympani by the cochlear partition

the corti (organ) located on the basilar membrane contains hair cells (hearing receptors)

Question 15

what’s the function of the cochlea?

Answer 15

hairs cells transduce mechanical vibrations into electrical signals

damage to hair cells can result in hearing loss

Question 16

What is a tonotopic map

Answer 16

hair cells are organised along a tonotopic map in the cochlea, with different regions responding to different frequencies.

Apex (apical region) responds to low frequencies
Base (basal region) responds to high frequencies

Question 17

what is the auditory pathway?

Answer 17

Nerve Relay:

auditory signals travel from cochlea through auditory nerves

signals pass through the brainstem, mid-brain + thalamus)

finally reach the primary auditory cortex (A1) in the brain, which also has a tontopic map

Question 18

What are the 2 cues in sound localisations

Answer 18

Binaural cues
Monaural cues

Question 19

What are binaural cues?

Answer 19

Temporal differences in sound arrival time between ears - helps to localise sounds

Question 20

What are monaural cues?

Answer 20

the way sound is reflected by the head and pinnae (outer ear) - helps determine sound location

Question 21

What’s the Wernicke’s area

Answer 21

locates in the superior temporal gyrus –> crucial for language comprehension

Question 22

What’s Wernicke’s aphasia

Answer 22

damage to Wernicke’s area
characterised fluent speech with poor comprehension

Question 23

What’s Broca’s aphasia

Answer 23

damage to the broca’s area
characterised by good comprehension but impaired speech fluency