The sense by which sound is detected. In vertebrates the organ of hearing is the ear. In higher vertebrates variation in air pressure caused by sound waves are amplified in the outer and middle ears and transmitted to the inner ear, where sensory cells in the cochlea (see organ of Corti) register the vibrations. The resulting information is transmitted to the brain via the auditory nerve. The ear can distinguish between sounds of different intensity (loudness) and frequency ( pitch).
Subjects: Zoology and Animal Sciences.