The thickness of the basilar membrane varies along the length of the cochlea. As a result, different regions of the membrane vibrate in response to ____________. The thickness of the basilar membrane varies along the length of the cochlea. As a result, different regions of the membrane vibrate in response to ____________.
a. different sound amplitudes
b. All of the other answers are correct.
c. different sound frequencies
d. sounds coming from different locations in the environment