Is that high pitched squealing or whistling noise that your hearing aid makes driving you crazy? I never realized how bad it was until one day when I was saying goodbye to my father. I was giving him a hug, and as I did so I told him that I loved him. The squealing noise that came out of his hearing aid made both of us jump! He told me that you get used to it, but I decided to investigate further to see if anything could be done.
I learned that the high pitched noise made by hearing aids is called “feedback”. So what causes hearing aid feedback? The noise is the result of the microphone picking up sounds made by the speaker in the device, and basically echoing it over and over making it sound like a squeal or a whistle. Several things can be done to reduce or eliminate this noise, but there are pros and cons associated with some of the solutions.
One of the most causes of hearing aid feedback is ear wax. Ear wax can cause a boundary between your hearing aid and your eardrum. The pressure from the sound waves leaving the device and travelling through the ear canal bounce back, and the waves are then picked back up by the microphone. This issue is easily resolved by having someone check your ears, and removing any wax build up that may be there. Even if you clean your ears regularly, some wax may build up deeper in the canal and cause hearing aid feedback.
Another very common cause of hearing aid feedback is a loose fit. Hearing aids are fitted so that there is no gap between the device and your ear canal. Something as simple as weight loss can cause minute changes in the diameter of your ear canal, resulting in squeals and whistles.
There are several ways to determine if a loose fit is causing hearing aid feedback. These are not guaranteed to tell whether or not this is the issue, but often times can give you a general idea. The first thing to do is to try pressing the hearing aid more firmly into the ear canal and see if this helps. You can also try plugging the vent with tape to see if that stops the noises. If there is a small gap, you can often detect it by placing a small amount of Vaseline on the hearing aid before inserting it. This may seal the gap, and reduce or eliminate the feedback which suggests the fit is too loose. The important thing to remember is that if you feel a loose fot is the cause of the feedback, you should see a specialist to get refit.
A final solution may be to use frequency response adjustments. By reducing the high frequencies picked up by your hearing aid, you can often times lower or eliminate the amount of feedback received. You should be aware though that reducing the high frequencies typically means you won’t be able to hear quite as well since it will also stop you from picking up the higher frequencies often used in everyday speech.
In the end, I think my father got it right. He hated his hearing aids when he first got them, and swore that he had just wasted a lot of money for nothing. After awhile though, he just got used to it.