the act or faculty of perceiving sounds. Hearing is reckoned among our external senses. Its organ is the ear, and particularly the auditory nerve diffused through the same; and its object, certain motions or vibrations of the air. Hence hearing may be more scientifically defined a sensation, by which, from a due motion impressed on the fibrilla of the auditory nerve, and communicated thence to the sensorium, the mind obtains the idea of sounds.