IHS Anatomy and Physiology of Hearing 4

Question 1

The endocochlear potential (EP) in the scala media is approximately:

Accepted Answer

+80 mV

Answer

The endocochlear potential is approximately +80 mV, created by the stria vascularis, and provides the driving force for K⁺ to enter hair cells during transduction.

Question 2

Otoacoustic emissions (OAEs) originate from:

Accepted Answer

Outer hair cell electromotility

Answer

OAEs are sounds generated by the active mechanical movements (electromotility) of outer hair cells and can be measured in the ear canal, reflecting cochlear health.

Question 3

Which ascending auditory pathway structure is primarily responsible for binaural processing and sound localization?

Accepted Answer

Superior olivary complex

Answer

The superior olivary complex is the first site where inputs from both ears converge, enabling interaural time and level difference processing for localization.

Question 4

Presbycusis (age-related hearing loss) predominantly affects hearing in which frequency range first?

Accepted Answer

High frequencies (4000–8000 Hz)

Answer

Presbycusis typically begins with high-frequency loss because the cochlear base, which processes high frequencies, is most exposed to cumulative noise and metabolic stress.

Question 5

The round window membrane functions to:

Accepted Answer

Allow perilymph displacement when the stapes moves

Answer

The compliant round window membrane bulges outward into the middle ear when the stapes pushes inward, allowing cochlear fluid to move and the basilar membrane to vibrate.

IHS - International Hearing Society Practice Test

IHS - International Hearing Society Practice Test

IHS Anatomy and Physiology of Hearing 4