Does your hearing aid sound a bit like a teakettle recently? A very common issue with hearing aids which can most likely be fixed is feedback. Understanding exactly how hearing aids operate and what is behind that incessant high pitched whistling noise will get you one step closer to eradicating it. But exactly what can be done?
How Do Hearing Aids Work?
Hearing aids, at their core, are really just a microphone and a speaker. The microphone picks up the sound and the speaker plays it back into your ear. But there are advanced functions in between when the microphone picks up the sound and when the speaker plays it back.
The sound is then changed to an analog electrical signal to be processed after entering the microphone. The analog rendition is then converted into digital by the device’s processor. Once the signal is converted to digital, the various features and settings of the hearing aids kick in to amplify and clean up the sound.
The signal is sent to a receiver after being modified back to analog by the processor. It’s not possible to hear these electrical signals that were once a sound. 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 to electrical signals for the brain to understand.
It all sounds very complicated but it happens in a nanosecond. Despite all of this state-of-the-art technology, the hearing aid still has feedback.
Feedback Loops And How They Happen
Hearing aids are not the only place where you find feedback. Systems that come with microphones generally have some degree of feedback. In essence, the microphone is picking up sound which is produced by the receiver and re-amplifying it. After entering the microphone and being processed, the receiver then transforms the signal back into a sound wave. The microphone then picks up that same sound wave again and amplifies it creating the feedback loop. The hearing aid hates hearing itself over and over again and that causes it to scream.
What Causes Hearing Aid Feedback?
There are quite a few things that could become a problem which could create this feedback loop. 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 starts to process sound as soon as you press the “on” button. The sound coming from the receiver bounces off your hand and then back into the microphone triggering the feedback. When your hearing aid is snuggly inside of your ear and then you turn it on, you will have eliminated this particular feedback hassle.
If your hearing aids aren’t fitting as well as they should, this can also lead to feedback. 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 need to head back to the retailer and have the piece re-adjusted so it will fit your ear properly again.
Earwax And Feedback
Earwax isn’t a friend of your hearing aids. Hearing aids usually won’t fit well if there is earwax built up on the casing. And we already learned that a loose fitting device can cause feedback. Look in the manual that came with your hearing aids or check with the retailer to determine how to clean earwax off safely.
Maybe It’s Only Broke
When you’ve attempted everything else but the feedback continues, this is where you head next. Feedback can certainly be caused by a broken or damaged hearing aid. For example, the outer casing might be cracked. It’s unwise to try to fix the unit on your own. Instead take it in for professional repair.
Occasionally What Sounds Like Feedback is Really Something Else Altogether
There is a chance that what you are hearing is actually not really feedback to begin with. Many hearing aids use sound to alert you of impending issues like a low battery. The sound should be carefully listened to. Is it a tone or a beep, or does it really sound like feedback? If your device comes with this feature, the manual will tell you.
It doesn’t matter what brand or style you use. Many brands of hearing aids are capable of producing it and the cause is typically very clear.