What is the function of the basilar membrane in hearing?

What is the function of the basilar membrane in hearing?

• A. It amplifies sound waves in the outer ear.
• B. It transduces electrical signals into vibrations.
• C. It creates tympanic membrane movement to regulate sound.
• D. It contains hair cells that transduce sound frequency into neural signals.

Answer: (D)

Understanding how the basilar membrane works helps explain why this option is correct. When sound travels through the cochlea, the basilar membrane vibrates in response to those pressure waves. Hair cells sit on top of this membrane, and their stereocilia bend in response to the motion. That bending opens ion channels, creating receptor potentials and triggering neural signals sent to the brain. The membrane’s stiffness varies along its length, so different frequencies peak at different locations, giving the auditory system a frequency map (tonotopy). The basilar membrane itself doesn’t amplify sound in the outer ear, nor does it transduce electrical signals into vibrations, nor does it create tympanic membrane movement. The hair cells contained on it are the actual transducers that convert mechanical energy into neural signals, which is why this statement best describes its function.

Understanding how the basilar membrane works helps explain why this option is correct. When sound travels through the cochlea, the basilar membrane vibrates in response to those pressure waves. Hair cells sit on top of this membrane, and their stereocilia bend in response to the motion. That bending opens ion channels, creating receptor potentials and triggering neural signals sent to the brain. The membrane’s stiffness varies along its length, so different frequencies peak at different locations, giving the auditory system a frequency map (tonotopy). The basilar membrane itself doesn’t amplify sound in the outer ear, nor does it transduce electrical signals into vibrations, nor does it create tympanic membrane movement. The hair cells contained on it are the actual transducers that convert mechanical energy into neural signals, which is why this statement best describes its function.