Are you beginning to hear a high pitch noise coming out of your hearing aids? A very common concern with hearing aids which can probably be fixed is feedback. That aggravating high pitched noise can be better understood by learning how your hearing aids operate. But exactly what can you do about it?
How Do Hearing Aids Work?
A simple microphone and a speaker are the core of a hearing aid. The speaker plays the sound into your ear which the microphone picks up. It’s what happens between the microphone and speaker that gets a little complicated.
The sound is then transformed into an analog signal to be processed after being picked up by the microphone. A sophisticated transformation from analog to digital is then performed by a signal processing chip. The sound is cleaned up after it becomes digital by the device’s functions and settings.
The signal is transmitted to a receiver after being changed back to analog by the digital signal processor. It’s not possible to hear these electrical signals that were once a sound. The receiver converts the signal back to sound waves and sends them through your ears. Ironically, the brain interprets sound by electrical signals, so elements in the cochlea translate it back into electrical signals for the brain to understand.
It’s hard to believe but all of this takes place in around a nanosecond. In spite of all of this advanced technology, the hearing aid still has feedback.
How do Feedback Loops Happen?
Hearing aids are not the only place where you notice feedback. Sound systems that include microphones normally have some level of feedback. Essentially, the microphone is picking up sound that is produced by the receiver and re-amplifying it. After entering the microphone and being processed, the receiver then converts the signal back into a sound wave. The microphone starts to pick up that same sound wave again and amplifies it creating the feedback loop. Put simply, the hearing aid is hearing itself and it doesn’t like it.
Exactly What is The Cause of Hearing Aid Feedback?
There are a number of things that might become a problem which could cause this feedback loop. 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 press the “on” button. The feedback is produced as the sound coming out of the receiver bounces off your hand and back into the microphone. The resolution to this problem is pretty simple; you should wait until the device is inside your ear before pressing the button.
Occasionally hearing aids don’t fit quite as well as they should and that can lead to feedback problems. Loose fitting devices have a tendency to be a problem with older hearing aids or if you’ve lost some weight since having them fitted. If that’s the case, you need to head back to where you got it and have the piece adjusted to fit your ear properly again.
Feedback And Earwax
Earwax isn’t a friend when it comes to hearing aids. Hearing aids won’t always fit right if there is an accumulation of earwax on them. When that happens, the device becomes loose again and produces feedback. If you consult your retailer or if you study the users-manual, you will determine how to safely clean this earwax off.
Perhaps It’s Simply Broken
This is your next thing to start thinking about when you’ve attempted everything else. 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. Take it in for expert repair.
When is Feedback Not Really Feedback
You may well be hearing something that sounds like feedback but it’s actually not. Many hearing aids use sound to alert you of impending problems 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.
Feedback doesn’t discriminate by brand or style. Many brands of hearing aids are going to produce it and the cause is typically quite clear.