Chap 10. Pt.II

Question 1

Harmonic

Answer 1

A component frequency of a complex waveform that, for periodic sounds, is an integer multiple of the fundamental frequency

Question 2

Timbre

Answer 2

The difference in sound quality between two sounds with the same pitch and loudness; for complex periodic sounds, timbre is mainly due to differences in the relative amplitudes of the sounds’ overtones or harmonics; the perceptual dimension of sound that is related to the physical dimension of waveform.

Question 3

Outer Ear components

Answer 3

Pinna
Auditory canal
Tympanic Membrane

Question 4

Pinna

Answer 4

Helps direct sound into ear canal

Aids in sound localisation

Question 5

Auditory canal

Answer 5

Funnels and modulates incoming sounds

resonant frequency – 2000 - 5000 Hz

Question 6

Tympanic membrane

Answer 6

converts air pressure changes into mechanical vibrations

Question 7

Middle Ear

Answer 7

The middle ear is responsible for amplifying and transmitting the sound signal between the outside air (eardrum) and the inner ear (oval window)
It contains three small bones that transmit the sound vibrations mechanically to the cochlea which is a liquid filled chamber

Question 8

3 bones of middle ear, what they do

Answer 8

Malleus, Incus, Stapes

• Ossicles act as a mechanical amplifier
• They do this in two ways:
• As a lever –malleus moves further than stapes
• As force focussing device – ear drum has much larger surface (20x) area than stapes

Question 9

Eustachian tube

Answer 9

A tube connecting the middle ear and the top part of the throat; normally closed but can be briefly opened ( e. g., by swallowing or yawning) to equalize the air pressure in the middle ear with the air pressure outside.

Question 10

Inner Ear Parts

Answer 10

Fluid, Stapes (attaches to cochlea at the oval window), Cochlea (Neural transduction occurs within the cochlea)

Question 11

Fluid-filled inner ear has two main components:

Answer 11

• cochlea
 (hearing)
• semi-circular canals
(vestibular function)
• Stapes attaches to cochlea at the oval window
• Cochlea is snail-shaped structure with three internal canals
• Neural transduction occurs within the cochlea

Question 12

vestibular system

Answer 12

The sense organs used to produce neural signals carrying information about
balance and acceleration;
includes the semicircular canals and the otolith organs.

Question 13

semicircular canals

Answer 13

Part of the vestibular system; three mutually perpendicular hollow curved tubes in the
skull filled with endolymph; responsible for singling head rotation.

Question 14

The Organ of Corti:

Answer 14

the auditory analogue of the retina
Is the site of neural transduction
Rests on the basilar membrane
Contains the hair cell receptors

Question 15

Basilar Memrane Displacement: Base, Middle and Apex (end)

Answer 15

• at thick stiff narrow base: big displace for high freq

* At thin wide loose apex: big displacement for low freq