What is feedback in hearing aids and why is it a problem?
Feedback refers to the high-pitched squealing or whistling that hearing aids sometimes make. Feedback occurs when sound already amplified by the hearing aid leaks from the ear canal back to the hearing aid microphone. This can happen when the hearing aid is not positioned correctly or when it does not fit securely enough in the ear canal to maintain a complete seal, creating unwanted space between the device and the ear canal. The presence of a high-pitched squealing noise can interfere with the ability to hear or participate in a conversation. In order to prevent feedback from occurring, tighter-fitting hearing aids or ear moulds are used to try to completely seal the ear canal. Because the ear canal changes shape when the mouth moves (for example, when talking, chewing, yawning, or laughing), achieving a complete seal is difficult. Feedback is often managed by reducing the amount of hearing aid gain (the amount of power the hearing aid creates to amplify sound). While reducing gain h
