Is that a teapot or is it just your hearing aids? Feedback is a common issue with hearing aids but it’s not something that can’t be fixed. If you would like to come one step closer to knowing why you keep hearing that high pitch whistling noise, you need to learn how your hearing aids operate. But exactly what can you do about it?
What Exactly Are The Functions of Your Hearing Aids?
As a basic rule, hearing aids are simply a microphone and a speaker. The microphone picks up the sound and the speaker plays it back in your ear. But there are advanced functions in between the time that the microphone picks up the sound and when the speaker plays it back.
After the sound enters the microphone it gets transformed to an electrical analog signal for processing. The analog version is then translated into a digital signal by the device’s digital signal processor. The sound is clarified after becoming digital by the device’s features 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 your ears can hear. The receiver converts the signal back to sound waves and sends them through your ear canal. Ironically, the brain interprets sound by electrical signals, so elements in the cochlea turn it back to electrical signals for the brain to understand.
It all sounds quite complicated but it happens in about a nanosecond. Despite all of this sophisticated technology, the hearing aid still has feedback.
Feedback Loops And How They Happen
Feedback occurs in other systems besides hearing aids. You hear that same whistle in most sound systems which use a microphone. Basically, the microphone is picking up sound that is coming from the receiver and re-amplifying it. After going into the microphone and getting processed, the receiver then converts the signal back into a sound wave. A feedback loop is then produced when the microphone picks up the sound again and re-amplifies it. Simply put, the hearing aid is hearing itself and it doesn’t like it.
What Causes Hearing Aid Feedback?
There are quite a few things that can 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. As soon as you press the on button, your hearing aid starts to process sound. The sound coming from the receiver bounces off your hand back into the microphone triggering the feedback. The answer to this problem is quite simple; you should wait until after the hearing aid is inside your ear before hitting the button.
Feedback can also be caused when your hearing aid isn’t fitting properly. Loose fittings tend to be a problem with older hearing aids or if you’ve lost weight since you last had them fitted. In that case, you need to head back to where you got it and have the piece adjusted so it will fit your ear properly again.
Earwax And Feedback
Earwax isn’t a friend when it comes to hearing aids. Hearing aids usually won’t fit right if there is earwax built up on the casing. And we already learned that a loose fitting device will cause feedback. If you ask your retailer or if you study the users-manual, you will find out how to safely clean this earwax off.
Perhaps It’s Only Broke
When you’ve tried everything else but the whistling continues, this is what you do next. Feedback can absolutely be caused by a broken or damaged hearing aid. For instance, the outer casing might be cracked. You should not attempt to fix this at home. Make an appointment with a hearing aid specialist to get a repair.
When is Feedback Not Really Feedback
You could very well be hearing something that you think sounds like feedback but it’s really not. A low battery or other possible issues will cause a warning sound in some devices. The sound should be carefully listened to. Is it really a whistling noise or does it sound more like a beep? Check the manual to see if your device has 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 capable of producing it and the cause is typically very clear.