HEARING, 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, whereby, from a due motion impressed on the fibrillæ of the auditory nerve, and communicated thence to the sensory, the mind perceives and gets the idea of sounds. See ANATOMY, No 141.