Audiphone, aw'de fone, or Dentiphone, an instrument by means of which deaf persons are enabled to hear. It consists essentially of a fan-shaped plate of hardened rubber, having a handle at one end and a string attached to the opposite end. The plate is bent downward by pulling on the string, thus forming a concave surface which collects the sound waves and transmits them to the teeth, from which they are conveyed to the auditory nerve through the bones of the face. The audiphone is of use to people whose deafness is caused by defects in the external or middle ear.