Hearing

Question 1

How do sound waves propagate?

Answer 1

As mechanical waves of pressure changes through some medium, with the speed of the wave depending on the medium

Question 2

How are differences in pressure changes measured?

Answer 2

In sound pressure level (SPL) measured in decibels

Question 3

How is sound pressure measured?

Answer 3

In micro pascals

Question 4

What is the auditory response area?

Answer 4

The psychophysically measured area that defines the combinations of frequencies and sound pressure levels (SPLs) over which hearing functions

Question 5

What is timbre?

Answer 5

The perceived quality that distinguishes between two tones that sound different even though they have the same loudness, pitch, and duration.

Question 6

How is the quality of transmission maintained in pressure differences going from air to the liquid of the cochlea?

Answer 6

The middle ear contains an amplifier which increases the quality of transmission. Also contains the smallest skeletal muscles in the body which tense as protection against painful sounds.

Question 7

What is a Fourier analysis?

Answer 7

Breaks complex waveforms into its pure tone components

Question 8

What is the function of the pinna

Answer 8

To help collect sound from the environment

Question 9

What are the 3 channels of the cochlea? What is the structure on the whole calles?

Answer 9

• The vestibular, timpanic and middle canals

- Entire structure is the organ of Corti

Question 10

How is sound perceived?

Answer 10

• Tectorial membrane vibrates according to sound waves

- Outer hair cells connected to the tectorial membrane bend and change the membrane potential

Question 11

What is a tonotopic map?

Answer 11

An ordered map of frequencies created by the responding of neurons within structures of the auditory system. There is a tonotopic map of neuron along
the length of the basilar membrane of the cochlea, with neurons in the apex responding best to low frequencies and neurons at the base responding best to high frequencies.

Question 12

How are membranes in the basilar membrane amplified?

Answer 12

By the bending of outer hairs

Question 13

What is the vestibular system?

Answer 13

The mechanism in the inner ear that is responsible for balance and sensing the position of the body

Question 14

How is sound localisation (azimuth, distance and eleation) achieved?

Answer 14

Through Interaural Level Difference (ILD) or pressure difference between left and right ear and the Interaural Time Difference (ITD)

Question 15

Define azimuth

Answer 15

Property of sound that specifies location from left to right

Question 16

What is the purpose of the ear cannal?

Answer 16

To transmit sound from the pinna to the eardrum

Question 17

What are the vestibular organs composed of?

Answer 17

3 semicircular cannals, cristae within ampullae and the otolith organs (utricle and saccule)

Question 18

How do the vestibular signal head orientation?

Answer 18

Semicircular canals work in pairs, one depolarizes hair cells and increases action potentials whist the other hyperpolarises and decreases action potential rate via the movement of endolymph

Question 19

What are the ossicles

Answer 19

The small bones in the ear