Copyright © American Speech-Language-Hearing Association From: Middle Ear Implantable Hearing Devices Am J Audiol. 2002;11(2):104-113. doi:10.1044/1059-0889(2002/019) Legend: A conventional hearing aid consists of a microphone, amplifier, processor, and speaker. Amplified acoustic energy entering the ear results in amplified vibrational energy in the ear. Because this amplified acoustic energy can feed back to the microphone, a tight fitting earmold must be used to seal the sound energy into the ear canal. Date of download: 10/5/2017 Copyright © American Speech-Language-Hearing Association