Lecture 9: Hearing

Question 1

The amplitude of a stimulus is experienced as

Answer 1

Loudness

Question 2

The frequency of a stimulus is experienced as

Answer 2

Pitch

Question 3

Human speech discrimination depends on tones in the range from _________, which is also the frequency of sound to which we are most
sensitive

Answer 3

1000 –
5000 Hz

Question 4

The part of the ear that is designed to amplify certain sound frequencies and
muffle others. In humans, sounds in the range 1000 – 5000 Hz are amplified

Answer 4

The pinna (external ear)

Question 5

What are the three small bones in the middle ear?

Answer 5

malleus, incus, and stapes

Question 6

Part of the ear that acts as an amplifier helping small mechanical forces of air molecules to move the fluid in the inner ear, by focusing the pressures from the large tympanic membrane on the small oval window

Answer 6

Middle ear

Question 7

Part of the ear that consists of a coil of three parallel canals, the vestibular canal, the middle canal and the tympanic canal; The whole structure is only 4 mm in diameter, but if unrolled would extend to about 40 mm

Answer 7

The Cochlea

Question 8

Cells responsive to different frequencies are found in different places at each level of the central auditory system

Answer 8

Tonotopic Organization

Question 9

Each ear consists of two rows of sensory cells: a single row of ~3500 _______ and ~12000 _______ arranged in three rows

Answer 9

Inner Hair cells; Outer Hair cells

Question 10

From each hair cell protrude tiny hairs called

Answer 10

Stereocilia

Question 11

Disorders of outer or middle ear prevent vibrations from reaching cochlea

Answer 11

Conduction Deafness

Question 12

Destruction of hair cells particularly cilia that arise due to genes, infections, exposure to toxins, or loud sounds, and some drugs

Answer 12

Sensorineural Deafness

Question 13

Rare cases involving damage to auditory cortex or the inputs to the auditory cortex, can be complex such as ‘word deafness’ in which the patient is only deaf to verbal stimuli and can hear non-verbal stimuli

Answer 13

Cortical Deafness

Question 14

Provides information as to the force of gravity on the body and the acceleration of the head

Answer 14

Vestibular Perception

Question 15

What are the 3 functions of the vestibular perception?

Answer 15

Balance, head in upright position, integrate head movements

Question 16

Arranged at right angles to one another filled with a fluid called endolymph, detect rotation and acceleration

Answer 16

Semicircular Canals