Behind-the-ear hearing aid: A hearing aid worn behind the ear. The device amplifies sounds more than most other types of hearing aids. Behind-the-ear (BTE) aids rest behind the ear. Sound is sent to the ear canal via the earmold and clear plastic tubing molded to fit in the outer ear area. BTEs are suitable for almost all types and degrees of hearing loss and are especially appropriate for infants and young children and for people with more severe hearing losses. See also: Hearing aid.