Audiology I-II-II

Question 1

Sound possesses two primary qualities that are decoded by the auditory system: ______

Answer 1

amplitude (or intensity) and frequency.

Question 2

The intensity of a sound increases when the air is compressed more forcefully during the peak compression in each cycle, resulting in ____________

Answer 2

increased density of air.

Question 3

The frequency is the number of times per second that a sound wave reaches the _________. Frequency is measured in Hertz (Hz, cycles/sec).

Answer 3

peak of rarefaction (or compression)

Question 4

The wavelength of sound (λ), given by: ___________

Answer 4

λ = velocity/frequency.

Question 5

An audiogram is a graph that shows the audible threshold for standardized frequencies as measured by an audiometer. The Y axis represents ______ and the X axis represents frequency measured in Hertz.

Answer 5

intensity measured in decibels

Question 6

An audiogram is a graph that shows the audible threshold for standardized frequencies as measured by an audiometer. The Y axis represents intensity measured in decibels and the X axis represents ________

Answer 6

frequency measured in Hertz.

Question 7

The threshold of hearing is plotted relative to a standardised curve that represents _______-, in dB(HL).

Answer 7

‘normal’ hearing

Question 8

SPL SOund pressure level

Answer 8

Ratio of pressures relative to a reference pressure

Question 9

The ___________ is the minimum sound level of a pure tone that an average ear with normal hearing can hear with no other sound present.

Answer 9

absolute threshold of hearing (ATH)

Question 10

Three parts of the ear

Answer 10

Outer ear
MIddle ear
Inner ear

Question 11

Pina

Answer 11

“ear” provides 20 decibels
gain
Outer ear

Question 12

Structure of the middle ear

Answer 12

Stapedius muscle- facial nerve

Tensor Tympani- trigem nerve

Question 13

Cochlea

Answer 13

is the auditory portion of the inner ear. It is a spiral-shaped cavity in the bony labyrinth

Question 14

Oval window

Answer 14

a membrane-covered opening which leads from the middle ear to the vestibule of the inner ear.

Question 15

Round window

Answer 15

sealed by the round window membrane, which vibrates with opposite phase to vibrations entering the inner ear through the oval window. It allows fluid in the cochlea to move, which in turn ensures that hair cells of the basilar membrane will be stimulated and that audition will occur.

Question 16

Ossicles

Answer 16

three bones in either middle ear that are among the smallest bones in the human body. They serve to transmit sounds from the air to the fluid-filled labyrinth (cochlea).

Question 17

Conductive vs sensorineural hearing losses

Answer 17

conductive= physical impedance

ex: otitis media

Question 18

Organ of corti

Answer 18

contains hair cells

Question 19

Paralymph

Answer 19

like CSF
In the ear (tympani and vestibule)
↑ Na
↓ K

Question 20

Endolymph

Answer 20

↑K
↓ NA
Scala media

Question 21

Hair cells

Answer 21

stereocilia (-50 mV resting)- Bathed in endolymph and paralymph
([K] difference)
80 mV electrochemical gradient

3 in outer row (12,000)
1 inner row (3,500)
16,000 total hair cell

Question 22

Sound energy–> electrical energy

Answer 22

happens in hair cells

Question 23

The Stereocilia - Tip Links

Answer 23

tension changes K channels–> hyperpolarizes the hair cell

Question 24

Congenital deafness

Answer 24

colapse of endochoclear potential- stria vasularis- K pump into scala media (mutation in k pump)

Question 25

Most hearing uses

Answer 25

inner hair cells

Question 26

acoustic impedance mismatch

Answer 26

Fluid is much more resistant to movement than air; in mechanical terms, water is said to have a high impedance, and air a low impedance. Because of this impedance mismatch, most of the sound’s energy (>99.9%) reaching an air-water interface is reflected back, and and

Question 27

composed of the pinna and external auditory meatus (ear canal) bounded by the tympanic membrane

Answer 27

external ear

Question 28

cavity containing the ossicular chain or 3 middle ear bones, malleus, incus and stapes

Answer 28

middle ear

Question 29

Outter layer hair cells are imbedded in

Answer 29

tectorial membrane (TM)

Question 30

The _______ is one of two acellular gels in the cochlea of the inner ear, the other being the basilar membrane (BM). located above the sulcus spiralis internus and the spiral organ of Corti and extends along the longitudinal length of the cochlea parallel to the BM

Answer 30

tectorial membrane (TM)

Question 31

• containing the cochlea and the semicircular canals (part of the vestibular system involved in detection of movement and maintaining balance to be discussed in later lectures)

Answer 31

inner ear

Question 32

Ototoxic drugs hurt

Answer 32

outer hair cells

Question 33

sensorineural hearing loss.

Answer 33

occurs from damage to or the loss of hair cells and or nerve fibers. Common causes are 1) excessively loud sounds; 2) exposure to ototoxic drugs (diuretics, aminoglygocide antibiotics, aspirin, cancer therapy drugs); and 3) age (presbycusis).

Question 34

conductive hearing loss.

Answer 34

When the mechanical transmission of sound energy through the middle ear is degraded

1) filling of the middle ear with fluid during otitis media (i.e., ear infection); 2) otosclerosis, in which arthritic bone growth impedes the movement of the ossicles; 3) malformations of the ear canal (atresia), including “swimmer’s” and “cauliflower” ear; 4) perforation/rupture of the tympanic membrane; 5) interruption of the ossicular chain; 6) static pressure in middle ear. Losses of 10-60 dB can occur in these cases.

Question 35

Oligochoclear nerve cells

Answer 35

x

Question 36

Cranial nerve 8 cell types

Answer 36

Type 1= IHC
Type 2= innervate OHC

There are a lot of nerves per IHC