Question

Identify the wrong statement regarding the mechanism of hearing.

• A. External ear receives and directs the sound waves to ear drum
• B. Vibrations produced in ear drum are transmitted through ear ossicles and oval window to fluid-filled inner ear
• C. Movement of basilar membrane bends the hair cells
• D. Nerve impulses are generated and transmitted by efferent fibres to the auditory cortex of brain
• E. Cerebellum integrates information from semicircular canals of ear and auditory system.

Answer 1

Answer: (D)

Nerve impulses are generated and transmitted by efferent fibres to the auditory cortex of brain

Mechanism of hearing is as follows:

• When sound waves from the environment enter the external ear, they are directed to ear drum (tympanic membrane).
• The ear drum vibrates on receiving sound waves and the vibrations are sent to oval window through ear ossicles which are malleus, incus and stapes.
• From the oval window, these vibrations are passed onto fluid of cochlea where waves are generated into lymph due to these vibrations.
• These waves generate vibrations in the basilar membrane which bend the hair cells and press them against the tectorial membrane.
• This results in the generation of nerve impulses in afferent neurons which are transmitted by afferent fibres to auditory cortex of brain.
• The impulses are analysed and recognised in brain.

Cerebellum integrates information about static equilibrium and motion or movement from semi-circular canals of ear and auditory system.

Hence, statement D is incorrect.

So, the correct answer is 'Nerve impulses are generated and transmitted by efferent fibres to the auditory cortex of brain'.