Are you starting to hear a high pitch noise coming out of your hearing aids? A very common problem with hearing aids which can probably be corrected is feedback. If you really want to come quite a bit closer to understanding why you keep getting that high pitch whistling noise, you should try to learn how your hearing aids function. So what can you do about it?
How Do Hearing Aids Work?
As a basic rule, hearing aids are simply a microphone and a speaker. The speaker plays the sound into your ear which the microphone picks up. When the microphone picks the sound up but before it gets played back by the speaker, there are some intricate functions that happen.
The sound is changed to an analog signal to be processed after entering the microphone. The analog rendition is then converted into a digital signal by the device’s digital signal processor. Once digital, the numerous features and settings of the device activate to amplify and clean up the sound.
The signal is sent to a receiver after being changed back to analog by the processor. It’s not possible to hear these electrical signals which were once a sound. The receiver converts the signal back to sound waves and transmits them through your ears. Ironically, the brain interprets sound by electrical signals, so elements in the cochlea translate it back into electrical signals for the brain to understand.
This all sounds very complex but it occurs in about a nanosecond. So if your hearing aid is so advanced why does it feedback?
Feedback Loops And How They Happen
Hearing aids are not the only place that you hear feedback. Systems with microphones normally have some amount of feedback. The receiver puts out sound which the microphone then picks up and re-amplifies. After entering the microphone and being processed, the receiver then transforms the signal back into a sound wave. The microphone starts to pick up that sound wave again and amplifies it producing the feedback loop. The hearing aid hates hearing itself over and over again and that causes it to screech.
What Causes Hearing Aid Feedback?
There are quite a few things that could go wrong to cause this feedback loop. If you turn on your hearing aid while it’s still in your hand prior to putting it in, you will get one of the most common causes. Right when you push the on switch, your hearing aid begins processing sound waves. The sound being produced by the receiver bounces off of your hand back into the microphone producing the feedback. If your hearing aid is snuggly inside of your ear before turning it on, you will have solved this particular feedback problem.
Feedback can also be caused when your hearing aid isn’t fitting as well as it should. Loose fitting devices have a tendency to be a problem with older hearing aids or if you’ve lost some weight since you last had them fitted. In that case, you should go back to the retailer and have the piece re-adjusted to fit your ear properly again.
Feedback And Earwax
Hearing aids certainly have issues with earwax. Hearing aids usually won’t fit well if there is an accumulation of earwax on them. When that takes place, the device becomes loose again and triggers feedback. Read the manual that came with your hearing aids or else contact the retailer to learn exactly how to clean earwax off without damaging the device.
Perhaps It’s Simply Broken
If all else fails you should take this into consideration. A damaged hearing aid will indeed feedback. The casing might have a crack in it somewhere, for example. You should not attempt to fix this at home. Schedule a session with a hearing aid repair service to get it fixed.
When is Feedback Not Really Feedback
Hearing aids can make other noises that you may think sound like feedback but are actually something else. Many hearing aids use sound to alert you of impending problems like a low battery. Listen to the sound. Is it a tone or a beep, or does it actually sound like feedback? Check your users-manual to see if your device includes this feature and what other warning sounds you should pay attention to in the future.
Feedback doesn’t discriminate by brand or style. Most hearing aids are going to produce it and the cause is usually very clear.