Does your hearing aid sound a little like a teakettle recently? A very common concern with hearing aids which can most likely be fixed is feedback. Understanding exactly how hearing aids work and what might be the reason for that constant whistling will get you one step closer to eradicating it. What can you do about hearing aid feedback?
What Exactly Are The Functions of Your Hearing Aids?
Hearing aids, at their core, are actually just a microphone and a speaker. The microphone picks up the sound and the speaker plays it back in your ear. When the microphone picks up the sound but before it gets played back by the speaker, there are some sophisticated functions that happen.
Once a sound wave enters the microphone it is converted into an analog signal for processing. An advanced transformation from analog to digital is then performed by a signal processing chip. Once the signal is converted to digital, the numerous features and controls of the hearing aids activate to intensify and clean up the sound.
The processor then changes the signal back to analog and transmits it to a receiver. It’s not possible to hear these electrical signals which were once a sound. The sound waves, which the receiver changes the signal back into, are then transmitted through your ear canal. Elements in the cochlea translate it back into an electrical signal that the brain can understand.
Amazingly all of this complex functionality takes place in a nanosecond. What goes wrong to cause the feedback whistle, though?
Feedback Loops And How They Happen
Feedback doesn’t exclusively happen in hearing aids. You hear that same whistle in the majority of sound systems that employ a microphone. The receiver puts out sound which the microphone then picks up and re-amplifies. The sound wave enters the microphone, goes through the processing and then the receiver transforms it into a sound wave. A feedback loop is then produced after the microphone picks up the sound again and re-amplifies it. Put simply, the hearing aid is hearing itself and doesn’t like it.
What Causes Hearing Aid Feedback?
A feedback loop might be caused by several difficulties. One of the most common causes is turning the hearing aid on while it’s still in your hand and then putting it in your ear. Your hearing aid begins processing sound waves right when you hit the “on” button. The sound being produced by the receiver bounces off of your hand and then back into the microphone causing the feedback. Before you decide to switch your hearing aid on put it inside of your ear and you will eliminate this source of feedback.
Feedback is sometimes caused when your hearing aid isn’t fitting properly. Loose fitting devices tend to be a problem with older hearing aids or if you’ve lost weight since you last had them fitted. Getting an adjustment from the retailer is the only good solution to this problem.
Feedback And Earwax
Hearing aids certainly have issues with earwax. Hearing aids won’t always fit correctly if there is earwax built up on the casing. And we already know that a loose fitting device will be the cause of feedback. Read the manual that came with your hearing aids or check with the retailer to learn how to clean earwax off safely.
Perhaps It’s Simply Broken
If everything else fails you should take this into consideration. Feedback will absolutely be caused by a broken or damaged hearing aid. The casing may have a crack in it somewhere, for example. You should not attempt to fix this damage at home. Instead take it in for expert repair.
When is Feedback Not Really Feedback
There is a chance that what you are hearing is not really feedback at all. Some hearing aids use sound to warn you of imminent problems like a low battery. The sound should be carefully listened to. Is it a tone or a beep, or does it really sound like feedback? If your device comes with this feature, the manual will tell you.
It doesn’t make a difference what brand or style you use. Many brands of hearing aids are going to produce it and the cause is typically pretty clear.