Hearing

Question 1

Pure Tone

Answer 1

Simple sinusoidal wave. Our voices and music and shit are not

Question 2

2 Parameters of Sound

Answer 2

Frequency - pitch
Pressure Level (decibels) loudness intensity

Question 3

Auditory Field

Answer 3

About 20 to 20k Hz, but conversation area greatly increased from like 300 to 3k Hz

Question 4

3 Functions of Outer Ear

Answer 4

Collect sound waves
Amplify sound pressure level
Frequency filter for localization of sound elevation

Question 5

Sound Force Amplification by ME

Answer 5

Pressure = F/SA and TM to oval window is 20:1 so it decreases SA. Lever effect of ossicular chain

Question 6

5 Differences b/w IHC and OHCs

Answer 6

Calix shaped, close to spiral ganglion, single row, afferent, 10 type 1 neurons synapse vs. columnar, far, 3 rows, contract for frequency tuning, and have 1 type II neurons connecting about 10

Question 7

2 Turns/Pitch Distribution

Answer 7

Apical turn for low freq/pitch sounds and basal turn for high

Question 8

Rapid Succession Mech

Answer 8

Calcium influx triggers motor prot which drives down tip link, reducing time constant of K channel opening, repolarizing the cell, and thus allowing cycles of mechanotransduction to occur in rapid succession (high freqs)

Question 9

Passive Tonotopy

Answer 9

Tonal separation dependent on physical properties of cochlea, where high freqs vibrate base and low vibrate apex where its less stiff

Question 10

Active Tonotopy

Answer 10

Finer mech via OHCs contracting at their very specific range, causing a 50 dB increase

Question 11

Frequency Preservation in Auditory Nerve

Answer 11

Bc auditory nerve fibers connect w/ IHC in approx 1:1 ratio, each auditory nerve fiber transmits information about only small part of audible freq spectrum. So apical nerves respond low freqs and etc

Question 12

2 Central Auditory Pathways

Answer 12

Primary: messages from cochlea

Non-primary: all types of sensory messages (reticular)

Question 13

Otoacoustic Emissions

Answer 13

Normal low level sounds produced by ear as part of hearing process. Can be reduced or absent in cases of certain types of hearing loss. Reflect activity of OHCs, most sensitive cells of organ of Corti so can be objective screening test in newborns (who can’t directly be tested) or adults at risk of hearing loss like workers

Question 14

Brainstem Auditory Evoked Potentials

Answer 14

See it going through auditory pathway (I. auditory n. II. cochlear nuclei III. Sup olive IV. lateral lemniscus V. Inf colliculus) and see if there’s any latency at the points indicating a problem. Additional tests for children/babies

Question 15

Bone-Air Gap

Answer 15

Means bone conduction is better than air, so there’s some sort of conductive hearing loss

Question 16

4 Treatments for OME

Answer 16

Antibiotics
Tympanostomy tubes
Adenoidectomy

Question 17

Treatment for Otosclerosis

Answer 17

Stapedectomy and replace w/ proper functioning synthetic one

Question 18

2 Treatments for Congenital Ear Canal Atresia

Answer 18

Atresia repair

Bone Anchored Hearing Aids (BAHA) - metal screw directly into bone and vibration goes to cochlea

Question 19

Aminoglycoside Ototoxicity (3)

Answer 19

Dose dependent damage to hair cells, can have genetic predisposition (often through mtDNA). Starts at cells w/ greater energy requirements (high freq) and progresses from OHCs to IHCs, base to apex

Question 20

Speech Audiogram w/ OHC Damage

Answer 20

Need 50 dB to just start picking up any sound, and never get 100% bc missing cells to tune to those words

Question 21

Cochlear Implant

Answer 21

Electrodes that process sound turn sound into electrical signals and placed inside cochlea at same tonotopic distribution

Question 22

2 Kinds of Noise Induced Hearing Loss

Answer 22

Temporary Threshold Shift (TTS)

Permanent (PTS)

Question 23

Sign of NILH on Pure Tone Audiometry Test

Answer 23

Backwards check mark at end

Question 24

Socio-acusis

Answer 24

Leisure noise exposure

Question 25

Presbycusis

Answer 25

Hearing of loss from age, hair cells damaged first then nerve fibers. High pitch goes first.

Question 26

Connexin 26

Answer 26

AR nonsyndromic, most comon cause of genetic hearing loss in children