Hearing

Question 1

measured in HERTZ

directly correlated w/ PITCH

Answer 1

FREQUENCY

human ear 20-20000 Hz

Question 2

measured in DECIBELS

directly correlated w/ AMPLITUDE (loudness/clarity)

Answer 2

INTENSITY/PRESSURE

60 dB - conversational speech
85 dB - limit to prevent occupational hearing loss
>120 dB - causes PAIN; triggers ATTENUATION REFLEX

Question 3

For sound localization and sound collection

Answer 3

OUTER EAR

pinna
external auditory canal

Question 4

For IMPEDANCE MATCHING - sound in air from outer ear is matched with sound in fluid in inner ear

Answer 4

MIDDLE EAR

tympanic membrane
auditory ossicles - malleus, incus and stapes

Question 5

Composed of BONY and MEMBRANOUS labyrinth

Answer 5

INNER EAR

bony labyrinth (semicircular canals, cochlea, vestibule)

Question 6

Seen in SCALA MEDIA/COCHLEAR DUCT

Answer 6

ENDOLYMPH

high in POTASSIUM

Question 7

Seen in SCALA VESTIBULI and SCALA TYPANI

Answer 7

PERILYMPH

high in SODIUM

Question 8

Inner hair cells near the BASE (oval and round windows)

NARROW and STIFF

Answer 8

responds to HIGH frequency sounds

Question 9

Inner hair cells near the HELICOTREMA (apex)

WIDE and COMPLIANT

Answer 9

responds to LOW frequency sounds

Question 10

Allows reflex adjustments of the head, eyes and postural muscles to provide stable visual image and steady posture

Answer 10

VESTIBULAR SYSTEM

Semicircular canals (3 perpendicular) - 
Otolith organs

Question 11

detect ANGULAR acceleration

Answer 11

Semicircular canals (3 perpendicular)

Question 12

detect POSITION of head in space

Answer 12

Otolith organs

utricle - HORIZONTAL (linear acceleration)
saccule - VERTICAL (linear acceleration)

Question 13

Happens when head rotated to the RIGHT

Answer 13

Both L and R ears deviate TOWARDS LEFT

Question 14

Stereocilia bends TOWARDS kinocilium

Answer 14

DEPOlarization

Question 15

Stereocilia bends AWAY from kinocilium

Answer 15

HYPERpolarization

Question 16

Direction of nystagmus

Answer 16

SAME direction as head rotation

Question 17

Direction of postrotatory nystagmus

Answer 17

OPPOSITE direction as head rotation

d.t. continued movement of endolymph in the semicircular canals with consequent bending of the cupula and (+) of hair cells

Question 18

Occupational Hearing Loss

Answer 18

85 dB x 8 hours x 10 years