Answer
The region of the basilar membrane closest to the oval window and the round window vibrates most vigorously to in response to high frequency sounds.
Work Step by Step
Sound waves of different frequencies cause certain areas of the basilar membrane to vibrate more frequently than others. Low-pitched sounds cause maximal vibration of the basilar membrane near the apex of the cochlea because there the basilar membrane is wider and more flexible. In contrast, high frequency sounds cause maximal vibration of the basilar membrane, near the base of the cochlea and close to the the oval window. There the basilar membrane is narrower, and stiff.
