One of the most common concerns hearing aid wearers have is, "Why is my hearing aid whistling?" The good news is that hearing aid feedback is often fixable and does not necessarily mean your hearing aid is faulty or broken. This article will explain the most of common causes of hearing aid feedback and how it can be addressed.

What Is Hearing Aid Feedback?

Very simply put, hearing aids consist of a amplifier, receiver (speaker), and microphones. The hearing aid microphones pick up sound around you which then gets amplified in the hearing aid, with the amplified sound then played out of speaker which either sits in your ear or is pushing sound into your ear. Some of that sound escapes back out of the ear where it is picked up by the microphones and reamplified, causing a loop. The result of this? A whistle or a squeal. Think about when you've been somewhere with a presenter speaking through a microphone. Sometimes if the microphone is too loud/sensitive and they stand near a speaker - we see a similar effect. This loop is called feedback.

Common Cause #1: Ear Wax

Ear wax can partially block the ear canal which can cause the sound coming out of the hearing aid speaker to reflect differently. This means that feedback becomes more likely. Think of the ear wax as kind of like a mirror, 'reflecting' the sound back out of the ear. So sometimes, resolving the whistling is just a matter of a simple wax removal appointment.

Common Cause #2: Poor Fitting Hearing Aid

There are several reasons why a poor fitting hearing aid would lead to hearing aid feedback. The hearing aid dome might be too small, or perhaps its not inserted correctly. If you have a custom mould, it's possible that it has become looser over time, or maybe you have lost a lot of weight and it's no longer fitting as well as it used to (yes, this happens!). A poor fitting hearing aid can mean that the hearing aid's acoustic coupling (dome or ear mould) is allowing more space around it which can let more sound escape, rather than having a good 'sealed' fitting in the ear canal. This is also why even well-fitted hearing aids need ongoing review.

Common Cause #3: Hearing Aid Settings

Sometimes the hearing aid itself is completely fine, but the settings and programming need adjusting. I mentioned earlier that "very simply put, hearing aids consist of a amplifier, receiver (speaker), and microphones", but in between all of this is a hearing aid computer chip which has immense capabilities and opportunities for advanced programming adjustments. We look at a number of things here, including the real-ear feedback management system, gain levels, further advanced programming adjustments, and of course acoustic coupling considerations to best account for what you physically have sitting in your ear.

Common Cause #4: Changes In Your Hearing

Now, your hearing changing does not have a direct effect on hearing aid feedback occurring. However, what I mean by this is that your hearing aids were set up to suit your hearing and needs when you last got them fitted/optimised. If it has been some time since then, and your hearing has deteriorated further - you might find yourself increasing the overall volume of the hearing aids much higher than what they were originally set up for. Changes to hearing can mean we need to explore new acoustic coupling options (e.g. different dome, transition from dome to ear mould, or new ear mould), new hearing aid prescription and gain adjustments, new feedback calibration - the list goes on. This is just another reason why hearing and hearing aid reviews are so important.

Common Cause #5: Physical Damage Or Wear

Physical damage can be things like the tubing of a behind-the-ear style hearing aid is cracked or hardened, or damage to hearing aid ear moulds. Once again, if we think about why feedback occurs - a lot of this starts to make more sense. For example, a cracked tube or ear mould can make the amplified sound escape from the hearing aid sooner than it is supposed to, and subsequently re-enter the microphone.

Can Modern Hearing Aids Prevent Whistling?

Yes, modern hearing aids are well equipped with many features that can help eliminate whistling. Modern feedback cancellation systems and technology in general have undergone significant improvements compared to older devices. However, as you can see from the above, no technology can completely overcome every acoustic problem. When you think about potential causes such as wax in the ears, poor fitting hearing aids, physical damage, or even changes to your hearing - an audiologist will be in the best position to help you identify and overcome the issue.

When Should You Seek Help?

If you've noticed the whistling is occurring constantly or frequently, its a recent change, your hearing seems to be getting worse, or the hearing aid itself has become uncomfortable to wear - these are all excellent reasons to see an audiologist. Audiology isn't a one-time sort of thing - the best outcomes are achieved with ongoing support and regular review. If you're having any trouble with your hearing or hearing aids - I would recommend seeking help.

Save My Hearing Aid

In many cases, people assume they need new hearing aids when the issue might actually be resolved through wax removal, maintenance, adjustments, reprogramming, or changes to the acoustic coupling. This is part of the reason as to why we at Solo Audiology and Hearing have our 'Save My Hearing Aid' appointment option. For a reliable, experienced, and trustworthy second opinion and optimisation.

Take Home Message

Hearing aid whistling is often a sign that something needs attention, but it doesn't necessarily mean your hearing aid is faulty. Ear wax, fit, programming, changes in hearing, and device maintenance can all contribute. A professional assessment can usually identify the cause and determine the most appropriate solution for you and your needs.

Written by Daniel Gerace, Clinical Audiologist and Owner of Solo Audiology and Hearing.