Woman suffering from feedback in her hearing aids covering her ears.

Is that a teakettle or is it just your hearing aids? A very common concern with hearing aids which can most likely be corrected is feedback. Understanding exactly how hearing aids operate and what might be the reason for that incessant high pitched whistling noise will get you a little closer to getting rid of it. But exactly what can be done?

What Exactly Are The Functions of Your Hearing Aids?

At their core, hearing aids are just a microphone and a speaker. The speaker plays back the sound in your ear that the microphone picks up. But there are intricate functions in between the time that the microphone picks up the sound and when the speaker plays it back.

The sound is translated into an analog electrical signal for processing after entering the microphone. A cutting edge digital processing microchip then changes the analog signal to digital. The sound is cleaned up after becoming digital by the device’s functions and settings.

The signal is transmitted to a receiver after being changed back to analog by the processor. You’re ears don’t hear these electrical signals which were once a sound. The receiver converts it back to sound waves and sends them through your ear canal. Ironically, the brain interprets sound by electrical signals, so elements in the cochlea translate it back into electrical signals for the brain to understand.

It’s hard to comprehend but all of this happens in a nanosecond. So if your hearing aid is so advanced why does it feedback?

How do Feedback Loops Occur?

Hearing aids are not the only place that you find feedback. If there is a microphone, it is likely that there is some amount of feedback. Essentially, the microphone is picking up sound which is produced by the receiver and re-amplifying it. The sound wave enters the microphone, goes through the signal processing and then the receiver turns it back into a sound wave. The microphone then picks up that same sound wave again and amplifies it creating the feedback loop. Simply put, the hearing aid is hearing itself and doesn’t like it.

What Causes Hearing Aid Feedback?

There are a number of things that might go wrong to create this feedback loop. If you turn on your hearing aid while it’s still in your hand before you put it in, you will get one of the most common causes. Your hearing aid begins processing sound waves right when you press the “on” switch. This feedback is produced when the sound coming out of the receiver bounces off of your hand and right back into the microphone. When your hearing aid is snuggly in your ear and then you turn it on, you will have resolved this particular feedback problem.

Feedback is sometimes caused when your hearing aid isn’t fitting properly. If you have lost weight since you had your hearing aids fitted, or if your hearing aids are older, you might have a loose fit. In that case, you should head back to the retailer and have the piece adjusted so it will fit your ear properly again.

Feedback And Earwax

With regards to hearing aids, earwax is in no way a friend. Hearing aids usually won’t fit right if there is earwax built up on the casing. And we are already aware that a loose fitting device can cause feedback. Look in the manual that you got with your hearing aids or else ask the retailer to learn how to clean earwax off safely.

Maybe It’s Only Broken

When you’ve attempted everything else but the feedback continues, this is what you do next. A damaged hearing aid will definitely feedback. For example, the outer casing may be cracked. It’s unwise to try to fix it on your own. Make an appointment with a hearing aid expert to get a repair.

Occasionally What Sounds Like Feedback is Actually Something Else Altogether

Hearing aids can make other noises that you may think sound like feedback but are in fact something else. Many hearing aids use sound to alert you of impending issues such as a low battery. The sound should be carefully listened to. Is it a tone or a beep, or does it really sound like feedback? Consult the manual to find out if your device comes with this feature and what other warning sounds you should pay attention to in the future.

It doesn’t matter what brand or style you have. Usually, the cause of the feedback is pretty clear no matter what brand you have.