Does your hearing aid sound a bit like a teakettle these days? A very common issue with hearing aids which can probably be corrected is feedback. If you want to come quite a bit closer to knowing why you keep hearing that high pitch whistling noise, you need to understand 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 into your ear which the microphone picks up. But there are complex functions between the time that the microphone picks up the sound and when the speaker plays it back.
After the sound enters the microphone it is translated into an analog signal to be further processed. A high-tech digital signal processing microchip then converts the analog signal to a digital one. The sound is cleaned up after it becomes digital by the device’s functions and controls.
The digital signal processor then transforms the signal back to analog and sends it to a receiver. At this stage, what was once a sound wave becomes an analog signal and that’s not something you can hear. The receiver converts it back into 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.
Amazingly all of this complex functionality happens in a nanosecond. In spite of all of this advanced technology, the device still has feedback.
Feedback Loops And How They Happen
Feedback occurs in other sound systems besides hearing aids. You hear that same whistle in most sound systems that employ a microphone. The receiver produces 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 sound is then re-amplified after the microphone picks it up again which produces a loop of feedback. Put simply, the hearing aid is hearing itself and it doesn’t like it.
What Causes Hearing Aid Feedback?
A feedback loop can be caused by several issues. One of the most common causes is turning the hearing aid on while it’s still in your hand and then putting it into your ear. Your hearing aid starts to process sound right when you hit the “on” switch. The sound being produced by the receiver bounces off of your hand and then back into the microphone triggering the feedback. The answer to this problem is pretty simple; you should wait until the hearing aid is inside your ear before hitting the switch.
Occasionally hearing aids won’t fit as well as they should and that leads to feedback. Loose fittings have a tendency to be a problem with older hearing aids or if you’ve lost weight since having them fitted. Getting it adjusted by the retailer is the only good solution to this problem.
Feedback And Earwax
Earwax isn’t a friend when it comes to hearing aids. One of the main reasons that 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 can be the cause of feedback. Look in the manual that you got with your hearing aids or else check with the retailer to find out how to clean earwax off without damaging the device.
Maybe It’s Simply Broken
This is your next thing to consider when you’ve tried everything else. Feedback can definitely be caused by a broken hearing aid. The casing might have a crack in it somewhere, for example. You should never try to fix this damage 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. There are a few other things that can go wrong with your hearing aids, like a low battery, which will give you a warning sound. Pay attention to the sound. Is it actually a whistling noise or does it sound more like a beep? Consult the users-manual to find out if your device includes this feature and what other warning sounds you should pay attention to in the future.
It doesn’t make a difference what brand or style you use. Most hearing aids are going to produce it and the cause is typically very clear.