Is that a teapot or is it just your hearing aids? The well-known problem of feedback in your hearing aids can possibly be corrected. Understanding exactly how hearing aids work and what is behind that incessant whistling will get you a little closer to eliminating it. But exactly what can be done?
How Do Hearing Aids Work?
A simple microphone and a speaker are the core of a hearing aid. The speaker plays back the sound into your ear which the microphone picks up. When the microphone picks up the sound but before it gets played back by the speaker, there are some complex functions that occur.
After the sound is picked up by the microphone it gets modified into an analog signal to be further processed. The analog form is then converted into a digital signal by the device’s digital signal processor. The device’s sophisticated features and settings activate to amplify and clean up the sound.
The processor then transforms the signal back to analog and sends it to a receiver. It’s not possible to hear these electrical signals which were once a sound. The waves of sound, that the receiver converts the signal back into, are then transmitted 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.
It all sounds quite complicated but it takes place in about a nanosecond. What happens to cause the feedback whistle, though?
Feedback Loops And How They Happen
Hearing aids are not the only place where you notice feedback. Systems that come with microphones usually have some amount of feedback. Essentially, the microphone is picking up sound that is coming from the receiver and re-amplifying it. After entering the microphone and getting processed, the receiver then converts the signal back into a sound wave. The sound is re-amplified after the microphone picks it up again which produces a loop of feedback. Simply put, 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 in your hand and then putting it in your ear. Your hearing aid begins processing sound right when you hit the “on” switch. The sound coming from the receiver bounces off your hand back into the microphone producing the feedback. The resolution to this concern is pretty simple; wait until after the device is inside your ear before pressing the switch.
Sometimes hearing aids don’t fit quite 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 weight since having them fitted. In that case, you need to go back to the retailer and have the piece re-adjusted so it will fit your ear properly again.
Feedback And Earwax
When it comes to hearing aids, earwax is not a friend. Hearing aids usually won’t fit right if there is an accumulation of earwax on them. And we already learned that a loose fitting device will cause feedback. Look in the manual that you got with your hearing aids or consult the retailer to determine exactly how to clean earwax off safely.
Perhaps It’s Only Broken
When you’ve tried everything else but the whistling continues, this is where you head next. Feedback will certainly be caused by a broken or damaged hearing aid. The casing may have a crack in it somewhere, for example. You should not try to fix this damage at home. Make an appointment with a hearing aid expert to get a repair.
Occasionally What Sounds Like Feedback is Really Something Else Entirely
You could very well be hearing something that you think sounds like feedback but it’s actually not. Some hearing aids use sound to alert you of imminent issues such as a low battery. The sound should be carefully listened to. Is it a tone or a beep, or does it actually sound like feedback? If your device includes this feature, the owners 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 quite clear.