Question

Explain the mechanism through which a sound produces a nerve impulse in the inner ear.

Answer 1

The external ear collects the sound waves through the pinna. The sound waves enters the external auditory canal and vibrates the tympanic membrane. The ear drum then vibrates the sound waves and conducts the sound waves to the middle ear where the ear ossicles increases the intensity of the sound waves. These vibrating sound waves are conducted through the oval window to the fluid in the cochlea. Consequently, a movement is created in the lymph. This movement produces vibrations in the basilar membrane, which in turn stimulate the auditory hair cells. These cells generate a nerve impulse, conducting it to the auditory cortex of the brain via afferent fibres. The auditory cortex region interprets the nerve impulse and sound is recognised.