Does your hearing aid sound a little like a teapot right now? Feedback is a common issue with hearing aids but it’s not something that can’t be fixed. Understanding how hearing aids work and what might be the reason for that constant high pitched whistling noise will get you a little closer to eliminating it. But exactly what can you do about it?
How Do Hearing Aids Work?
As a basic rule, hearing aids are simply a microphone and a speaker. When a sound is picked up by the microphone, the speaker then plays it back in your ears. But there are advanced functions between when the microphone picks up the sound and when the speaker plays it back.
The sound is then converted to an analog signal to be processed after entering the microphone. An advanced transformation from analog to digital is then carried out by a signal processing microchip. The device’s sophisticated features and settings activate to amplify and clean up the sound.
The signal is transmitted to a receiver after being changed back to analog by the processor. At this point, what was once a sound becomes an analog signal and that isn’t something your ears can hear. The sound waves, which the receiver changes the signal back to, are then sent through your ears. Ironically, the brain interprets sound by electrical signals, so elements in the cochlea translate it back to electrical signals for the brain to understand.
Amazingly all of this complicated functionality takes place in a nanosecond. What goes wrong to cause the feedback whistle, though?
How do Feedback Loops Happen?
Hearing aids are not the only place that you find feedback. You hear that same high pitched noise in many sound systems which employ a microphone. In essence, the microphone is picking up sound which is produced by the receiver and re-amplifying it. The sound wave enters the microphone, then goes through the signal processing and then the receiver turns it back into a sound wave. The microphone starts to pick up that sound wave again and amplifies it creating the feedback loop. The hearing aid hates hearing itself over and over again and that makes it scream.
Exactly What is The Cause of Hearing Aid Feedback?
There are a number of things that can go wrong to cause this feedback loop. If you turn your hearing aid on in your hand before you put it in, you will get a very common cause. Your hearing aid begins processing sound as soon as you hit the “on” switch. The feedback is triggered when the sound coming out of the receiver bounces off of your hand and then back into the microphone. The answer to this difficulty is quite simple; you should wait until the hearing aid is inside your ear before hitting the button.
In some cases hearing aids don’t fit as well as they ought to and that leads to feedback problems. Loose fittings tend to be a problem with older hearing aids or if you’ve lost some weight since you last had them fitted. If that’s the case, you should go back to where you got it and have the piece adjusted so it will fit your ear properly again.
Earwax And Feedback
Earwax isn’t a friend when it comes to hearing aids. One of the major explanations for why hearing aids don’t fit right is because of the accumulation of earwax on the casing. And we already learned that a loose fitting device can be the cause of feedback. If you ask your retailer or if you read the manual, you will determine how to safely clean this earwax off.
Maybe It’s Only Broke
When you’ve attempted everything else but the feedback continues, this is where you head next. Feedback can 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 at home. Take it in for professional repair.
Sometimes What Sounds Like Feedback is Really Something Else Entirely
Hearing aids will make other noises that sound like feedback but are actually something else. A low battery or other potential problems can cause a warning sound in some devices. The sound should be carefully listened to. Is it a tone or a beep, or does it actually sound like feedback? If your device comes with this feature, the manual will tell you.
It doesn’t matter what brand or style you own. Many brands of hearing aids are going to produce it and the cause is usually very clear.