Hearing Mechanisms Quiz

A 35-year-old man presents with a complaint of decreased hearing in his right ear after a middle ear infection. Otoscopic examination reveals fluid behind an intact tympanic membrane. Which of the following best explains the reduced hearing in this patient?

• Damage to cochlear hair cells

• Disruption of ossicular chain conduction

• Rupture of the round window

• Increased stiffness of the basilar membrane

• Degeneration of auditory nerve fibers

A 28-year-old musician notices a gradual loss of hearing for high-frequency sounds. Audiometry confirms high-frequency sensorineural hearing loss. Which part of the basilar membrane is most likely affected?

• Near the oval window at the base of the cochlea

• Near the helicotrema at the apex of the cochlea

• Near the middle turn of the cochlea

• Within the semicircular canals

• At the round window

A researcher applies a drug that selectively inhibits outer hair cells of the cochlea in experimental animals. Which of the following changes is most likely to be observed?

• Loss of frequency discrimination

• Increased auditory threshold

• Complete deafness

• Loss of endolymph production

• Inability to transmit action potentials in auditory nerve

A 50-year-old man with a history of noise exposure has bilateral sensorineural hearing loss. Which of the following best describes the function of the stapedius muscle in protecting the inner ear from loud sounds?

• It increases cochlear blood flow

• It stiffens the ossicular chain, reducing sound transmission

• It opens the Eustachian tube to equalize pressure

• It dampens tympanic membrane movement

• It shifts the tectorial membrane away from hair cells

A sound wave with a frequency of 100 Hz stimulates the cochlea. Which of the following best explains how this frequency is encoded?

• By the amplitude of basilar membrane vibration

• By the number of outer hair cells activated

• By the specific region of the basilar membrane stimulated

• By the shape of the tympanic membrane

• By the duration of stimulation of inner hair cells

Which of the following best describes the immediate effect when the stereocilia of inner hair cells are deflected toward the tallest stereocilium?

• Hyperpolarization of hair cell membrane

• Inhibition of K⁺ influx

• Opening of mechanically gated K⁺ channels

• Decrease in neurotransmitter release

• Movement of tectorial membrane away from basilar membrane

A 45-year-old factory worker has difficulty hearing after years of exposure to machinery noise. Audiometry confirms bilateral high-frequency hearing loss. What is the most likely histological change in his cochlea?

• Necrosis of spiral ganglion neurons

• Degeneration of outer hair cells at the cochlear base

• Rupture of the Reissner's membrane

• Calcification of the tectorial membrane

• Obliteration of the scala tympani

A mutation disrupts K⁺ recycling in the cochlea. Which cochlear compartment is most directly affected by this disruption in terms of ionic composition?

• Scala tympani

• Scala vestibuli

• Scala media

• Tectorial space

• Basilar membrane

A diver reports muffled hearing after a rapid descent. Which structure-function relationship in the middle ear aids impedance matching between air and cochlear fluid?

• Round window vibration

• Tensor tympani contraction

• Tympanic membrane-oval window area ratio

• Endolymph movement

• Basilar membrane stiffness

Which of the following correctly describes the action of the tensor tympani muscle during the attenuation reflex?

• It pulls the stapes inward

• It pushes the malleus outward

• It pulls the handle of the malleus inward

• It contracts to vibrate the tympanic membrane

• It relaxes to allow more vibration