The number of cycles a sound wave completes in one second. Higher frequency results in higher pitched sounds, just like a faster spinning merry-go-round creates a higher-pitched sound.
A structure inside the cochlea that vibrates when stimulated by sound waves. Different sections along the basilar membrane vibrate in response to different frequencies, allowing us to distinguish between pitches, similar to how different strings on a guitar produce distinct notes.
A theory that explains how we perceive pitch based on the location along the basilar membrane that vibrates. This theory suggests that specific areas along the membrane are responsible for detecting specific frequencies, similar to keys on a piano producing specific notes when pressed.