1 Sound reception: the ear

In order to hear a sound, the auditory system must accomplish three basic tasks. First it must deliver the acoustic stimulus to the receptors; second, it must transduce the stimulus from pressure changes into electrical signals; and third, it must process these electrical signals so that they can efficiently indicate the qualities of the sound source such as pitch, loudness and location. How the auditory system accomplishes these tasks is the subject of much of the rest of this block. We will begin by describing the basic structure of the ear, which carries out the first of the three tasks.

The human ear can be divided into three fairly distinct components according to both anatomical position and function: the outer ear, which is responsible for gathering sound energy and funnelling it to the eardrum; the middle ear which acts as a mechanical transformer; and the inner ear where the auditory receptors (hair cells) are located.