Module 24 - Hearing

Question 1

Audition

Answer 1

The sense or act of hearing

Question 2

Frequency

Answer 2

The number of complete wavelengths that pass a point in a given time

Question 3

Pitch

Answer 3

A tone’s experienced highness or lowness; depends on frequency

Question 4

How does wavelength affect sound?

Answer 4

The shorter the wavelength, the higher-pitched the sound. The longer the wavelength, the lower-pitched the sound.

Question 5

How does amplitude affect sound?

Answer 5

The higher the amplitude, the louder the sound. The lower the amplitude, the softer the sound.

Question 6

Middle ear

Answer 6

The chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window

Question 7

Cochlea

Answer 7

A coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses

Question 8

Inner ear

Answer 8

The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs

Question 9

How do our ears pick up sound?

Answer 9

Sound waves strike the eardrum, causing it to vibrate. In the middle ear, three bones pick up the vibrations and transmit them to the cochlea, which causes its opening (oval windows) to vibrate. This causes the fluid inside it to vibrate, resulting in ripples in the basilar membrane and thus bending the hair cells lining its surface. This triggers impulses in adjacent nerve cells which converge to form the auditory nerve, which transmits neural messages to the thalamus and then on to the auditory cortex in the brain’s temporal lobe.

Question 10

Sensorineural hearing loss

Answer 10

Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; the most common form of hearing loss, also called nerve deafness

Question 11

Conduction hearing loss

Answer 11

A less common form of hearing loss, caused by damage to the mechanical system that conducts sounds waves to the cochlea

Question 12

Cochlear implant

Answer 12

A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

Question 13

Place theory

Answer 13

Links the pitch we hear with the place where our cochlea’s membrane vibrates

Question 14

Frequency (temporal) theory

Answer 14

The rate of nerve cells traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch