Most of us have heard it. That shrill whistle from a hearing aid if you get too close or as you take the hearing aid out. We have all experienced sitting near someone in public who seems to be unaware that they are “squealing”. That noise has a name and it is called “feedback”. If you have ever been to a concert or a presentation where a person is using a microphone and a loud “screech” is heard, that is feedback on a larger scale. What is happening is the microphone is “hearing” the sound coming out of the speaker. In a hearing aid, the speaker is typically in a person’s ear and the microphone is on the outside of the ear. If the sound from the speaker is “leaking” out of the ear too much, the microphone will turn up the amplified sound and create an acoustic “loop”, which we hear as a high pitch whistle sound. It’s just a fact that the louder the volume of the hearing aid, the more there is risk of feedback.
There is typically nothing wrong with the hearing aid, but it may mean there is something wrong with the way the hearing aid is fitting into the ear canal, or a concern with the person not putting the hearing aid on correctly. A “snug fit” is best to prevent feedback. The good news is, within the past few years, newer technology has really improved the ability to “cancel out” that feedback noise, and custom hearing aids and ear-molds are made to fit the ear canal more precisely. There are many solutions to what seem to be minor annoyances. Don’t be afraid to visit your Audiologist and let them know if you are experiencing any problems.