Audio Life Hearing Center- Knoxville, TN

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

Are you beginning to hear an annoying high pitch noise coming out of your hearing aids? A very common problem with hearing aids which can probably be corrected is feedback. That aggravating high pitched sound can be better comprehended by learning how your hearing aids work. But exactly what can be done?

How Do Hearing Aids Work?

As a basic rule, hearing aids are just a microphone and a speaker. The speaker plays the sound in your ear that the microphone picks up. When the microphone picks up the sound but before it is played back by the speaker, there are some complicated functions that occur.

After the sound is picked up by the microphone it is modified to an analog signal for processing. The analog rendition is then converted into a digital signal by the device’s digital signal processor. Once digital, the numerous features and controls of the device activate to intensify and clarify the sound.

The signal is sent to a receiver after being modified back to analog by the processor. At this stage, what was once a sound becomes an analog electrical signal and that isn’t something your ears can hear. The receiver converts the signal back into sound waves and sends them through your ears. Elements in the cochlea turn it back into an electrical signal that the brain can understand.

Surprisingly all of this complicated functionality happens in a nanosecond. What goes wrong to cause the feedback whistle, though?

How do Feedback Loops Occur?

Hearing aids are not the only place that you notice feedback. Sound systems that come with microphones usually have some degree of feedback. Essentially, the microphone is picking up sound that is produced by the receiver and re-amplifying it. The sound wave enters the microphone, goes through the signal processing and then the receiver transforms it into a sound wave. A feedback loop is then produced when the microphone picks up the sound again and re-amplifies it. The system doesn’t like hearing itself over and over again and that causes it to scream.

What Causes Hearing Aid Feedback?

A feedback loop can be caused by several difficulties. If you turn your hearing aid on in your hand prior to putting it in, you will get a very common cause. Right when you push the on switch, your hearing aid starts to process sound waves. The sound being produced by the receiver bounces off your hand back into the microphone creating the feedback. The answer to this difficulty is pretty simple; wait until the device is snuggly in your ear before pushing the switch.

If your hearing aids don’t fit that well, this can also cause feedback. If you have lost some weight since you had your hearing aids fitted, or possibly if your hearing aids a bit older, you might have a loose fit. In that case, you need to go back to the retailer and have the piece adjusted to fit your ear properly again.

Earwax And Feedback

Earwax isn’t a friend of hearing aids. One of the major explanations for why hearing aids don’t fit properly is because of the accumulation of earwax on the casing. And we are already aware that a loose fitting device will be the cause of feedback. If you consult your retailer or maybe if you read the users-manual, you will learn how to safely clean this earwax off.

Perhaps It’s Just Broken

If all else doesn’t work you need to consider this. A broken hearing aid will indeed cause feedback. The casing might have a crack in it somewhere, for example. It’s unwise to try and fix it on your own. Make an appointment with a hearing aid specialist to get a repair.

When is Feedback Not Really Feedback

You may well be hearing something that sounds like feedback but it’s actually not. There are things that can go wrong with your hearing aids, like a low battery, which can give you a warning sound. Listen closely to the sound. Is it a tone or a beep, or does it actually sound like feedback? If your device has this feature, the manual will tell you.

Feedback doesn’t discriminate by brand or style. Many brands of hearing aids are going to produce it and the cause is usually pretty clear.

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