Is that a teapot or is that just your hearing aids? Feedback is a very common problem with hearing aids but it’s not something that you can’t have fixed. Understanding exactly how hearing aids work and what might be the reason for that annoying whistling will get you a little closer to eliminating it. But exactly what can be done?
How Do Hearing Aids Work?
At their core, hearing aids are just a microphone and a speaker. The microphone picks up the sound and the speaker plays it in your ear. It’s what happens between the microphone and speaker that gets complicated.
Because the sound is going to be further processed, it must first be changed into an analog signal. The analog version is then translated into digital by the device’s digital signal processor. Once the signal is converted to digital, the various features and controls of the device activate to intensify and clarify the sound.
The signal is transmitted to a receiver after being changed back to analog by the digital signal processor. At this stage, what was once a sound becomes an analog signal and that’s not something your ears can hear. The receiver converts it back to sound waves and sends them through your ears. Elements in the cochlea convert it back into an electrical signal that the brain can understand.
Amazingly all of this complex functionality takes place in a nanosecond. What happens to cause the feedback whistle, though?
Feedback Loops And How They Happen
Hearing aids are not the only place that you notice feedback. If there is a microphone, it is likely that there is some amount of feedback. Basically, the microphone is picking up sound that is coming from the receiver and re-amplifying it. The sound wave enters the microphone, then goes through the signal processing and then the receiver turns it back into a sound wave. The sound is re-amplified after the microphone picks it up again which creates a loop of feedback. Simply put, the hearing aid is listening to itself and it doesn’t like it.
Exactly What is The Cause of Hearing Aid Feedback?
A feedback loop may be brought about by several issues. 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 waves as soon as you hit the “on” button. The feedback is caused as the sound coming out of the receiver bounces off your hand and then right back into the microphone. The answer to this difficulty is pretty simple; wait until the device is inside your ear before pushing the switch.
In some cases hearing aids don’t fit quite as well as they ought to and that leads to feedback. Loose fitting devices have a tendency to be a problem with older hearing aids or if you’ve lost weight since you last had them fitted. If that’s the case, you should go back to the retailer and have the piece re-adjusted to fit your ear properly again.
Earwax And Feedback
Earwax isn’t a friend when it comes to hearing aids. Hearing aids won’t always fit correctly if there is an accumulation of earwax on them. When that occurs, the device becomes loose again and causes feedback. Read the manual that came with your hearing aids or else consult the retailer to learn how to clean earwax off safely.
Perhaps It’s Just Broken
When you’ve attempted everything else but the feedback continues, this is what you do next. Feedback can certainly be caused by a damaged hearing aid. The casing may have a crack in it somewhere, for example. You should never try to fix this at home. Instead take it in for professional repair.
When is Feedback Not Really Feedback
Hearing aids can make other noises that sound like feedback but are really something else. A low battery or perhaps other potential issues will cause a warning sound in some devices. The sound should be carefully listened to. Is it a tone or a beep, or does it actually sound like feedback? Consult your 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 usually very clear.