Auditory Systems

Question 1

describe the sound attenuation reflex

Answer 1

when there are sustained loud sounds, the sound attenuation reflex helps to protect the inner ear from damage

• it limits the movement of the ossicular chain
• activation of the tensor tympani muscle (attached to the malleus; CN V) limits the movement of the tympanic membrane
• activation of the stapedius muscle (attached to the stapedius; CN VII) limits the movement of the stapedius

Question 2

describe the elements of the auditory pathways

Answer 2

Question 3

Answer 3

Question 4

does a central lesion in the auditory cortex cause hearing loss?

Answer 4

Question 5

does a peripheral lesion cause hearing loss?

Answer 5

Question 6

lesions in which structure produce unilateral hearing loss vs. no hearing loss?

Answer 6

• unilateral hearing loss
  
  • ear
  • CN VIII
  • cochlear nuclei
• no hearing loss
  
  • damage to auditory cortex

Question 7

describe the tonotopic organization of the primary auditory cortex

Answer 7

Question 8

describe the location of the primary auditory cortex and the associated Brodmann’s areas

Answer 8

• primary auditory cortex aka A1 is located on the transverse temporal gyrus aka Heschl’s gyrus aka BA 41 and 42

Question 9

describe what presbyacusis/presbycusis is

Answer 9

• age-related hearing loss
• progressive bilateral and symmetrical sensorineural hearing loss associated with aging, with higher frequencies being affected most

Question 10

describe Rinne’s test

Answer 10

• normal (Rinne positive): AC > BC
• conductive loss (Rinne negative): BC > AC

Question 11

during Weber’s test in patients with conductive hearing loss in one ear, the sound lateralizes to the _____ side of the damaged ear

Answer 11

during Weber’s test in patients with conductive hearing loss in one ear, the sound lateralizes to the ipsilateral side of the damaged ear

Question 12

during Weber’s test in patients with sensorineural hearing loss in one ear, the sound lateralizes to the _____ side of the damaged ear

Answer 12

in patients with sensorineural hearing loss in one ear, the sound lateralizes to the contralateral side of the damaged ear (towards the unaffected ear)

Question 13

if Rinne’s test shows both ears AC > BC, explain:

Weber w/o lateralization

Weber lateralizes left

Weber lateralized right

Answer 13

Question 14

if Rinne’s test shows left ear BC > AC, explain:

Weber lateralizes left

Weber lateralized right

Answer 14

Question 15

if Rinne’s test shows right ear BC > AC, explain:

Weber lateralizes left

Weber lateralized right

Answer 15

Question 16

if Rinne’s test shows both ears BC > AC, explain:

Weber w/o lateralization

Weber lateralizes left

Weber lateralized right

Answer 16