AP Psychology – Biological Bases of Behavior Practice Test

Pitch is determined by the location of vibration in the cochlea. The cochlea contains a structure called the basilar membrane, which varies in thickness and stiffness along its length. Different frequencies of sound waves cause vibrations at specific locations on this membrane. High-frequency sounds, for example, stimulate hair cells near the base of the cochlea, while low-frequency sounds vibrate hair cells closer to the apex. This tonotopic organization allows the brain to interpret the frequency of a sound, which we perceive as its pitch. Understanding this aspect of auditory perception highlights how our sensory systems translate physical properties of sound into neural signals that we can recognize and differentiate.