B7.041 Hearing Loss

Question 1

is lauren a dumb ho

Answer 1

yup the Prework notecards for this lecture are in the BMB 1 folder

Question 2

is hearing loss funny

Answer 2

no

but easter bunny humor can be appreciated on occasion

Question 3

epidemiology of hearing loss

Answer 3

common and increase with age
47% by age 75
only 1 in 5 that would benefit from a hearing aid wears one

Question 4

signs in hearing impaired children

Answer 4

difficulties in learning to speak
learning disabilities
delayed emotional and personality development
early diagnosis and intervention is critical

Question 5

how is hearing measured subjectively

Answer 5

soundproof booth
pure tones presented separately to each ear
vary frequency and intensity
determine threshold as a function of frequency
determine ability to discriminate speech sounds

Question 6

20 dB increase

Answer 6

10x increase in sound intensity

Question 7

intensity range of human hearing

Answer 7

120 dB

Question 8

human frequency range

Answer 8

20-20,000 Hz
125-8,000 Hz is usually what is tested
thresholds vary by frequency

Question 9

audiogram

Answer 9

thresholds plotted relative to average normal threshold at each frequency

Question 10

conductive hearing loss

Answer 10

impaired conduction of sound through external and middle ear up to inner ear

Question 11

sensorineural hearing loss

Answer 11

pathology of inner ear or CN VIII

Question 12

central hearing loss

Answer 12

CNS damage

relatively uncommon

Question 13

distinction between sensorineural and conductive hearing loss

Answer 13

air conduction vs bone conduction thresholds

Question 14

air conduction

Answer 14

normal route by which airborne sound reaches cochlea

Question 15

bone conduction

Answer 15

vibrating probe is applied to the skull

vibrations transmitted directly to cochlea bypassing middle ear

Question 16

hearing loss seen with air conduction

Answer 16

conductive + sensorineural

Question 17

hearing loss seen with bone conduction

Answer 17

sensorineural only

Question 18

audiogram of a patient w normal hearing

Answer 18

both bone and air conductions are at thresholds between 0-20 dB

Question 19

causes of sensorineural hearing loss

Answer 19

high intensity sound
ototoxic drugs
menier's disease (too much endolymph)
presbycusis (aging, high frequency goes first)
perinatal infection (rubella)
hereditary

Question 20

ototoxic drugs

Answer 20

aspirin
aminoglycosides
loop diuretics
cisplatin
quinine

Question 21

OHC vs IHC loss

Answer 21

OHC more vulnerable to damage
IHC loss = deafness
OHC loss = 30-40 dB loss

Question 22

treatment of sensorineural hearing loss

Answer 22

hearing aids, amplify sound

Question 23

common caused of conductive hearing loss

Answer 23

impacted cerumen in external ear canal
otitis media
otosclerosis
generally mild to moderate hearing loss of <30 dB

Question 24

how to measure hearing in babies

Answer 24

auditory evoked potentials (ABR)

otoacoustic emissions

Question 25

auditory brainstem response (ABR)

Answer 25

rapid, objective, noninvasive
measure of CN VIII and central auditory pathway
recorded using surface electrodes

Question 26

otoacoustic emissions

Answer 26

rapid, objective, noninvasive
measure of outer hair cell function (motility)
recorded using small microphone in ear canal
detected in presence of normal hearing

Question 27

cochlear implants

Answer 27

provide direct stimulation

Question 28

tinnitus

Answer 28

perception of phantom sounds
often accompanies hair cell loss
mild to debilitating, can lead to depression
often of CNS origin (cutting nerve doesn’t help)

Question 29

objective tinnitus

Answer 29

pulsing blood vessel

Question 30

subjective tinnitus

Answer 30

dysfunction in auditory system (more common)