Have you ever heard someone’s hearing aid buzzing and whistling? Nobody wants their hearing aids to whistle. Hearing aid feedback happens for two reasons: either the hearing aid doesn’t fit correctly or there is too much power. In both cases, sound from the hearing aid leaks out of the ear and is re-amplified by the hearing aid, causing the annoying high-pitched squeal.
Hearing aid feedback used to be a huge factor when recommending instruments for our patients. In the past, we would occlude the ear with a mold or the shell of a hearing aid to prevent sound from leaking out of the ear. This prevented feedback, but also caused an unwanted effect: to the wearer, their own voice sounded like they were in a barrel or a cave.It wasn’t until Starkey revolutionized the industry by introducing venting technology — allowing the provider to open up the earmold to reduce occlusion. Now the most common style of hearing aid dispensed in our offices is the open-fit, behind-the-ear device. This allows us to amplify the patients’ hearing aids to prescriptive levels without any feedback issues.
Today, patients can enjoy virtually feedback-free listening because of cancellation circuitry such as the PureWave Feedback Eliminator. Another benefit is the hearing aids’ power settings can be increased if the patient’s hearing requires a stronger prescription later, without causing the instrument to feedback and squeal. Why is this important? As time goes on, patients tend to lose more and more hearing, i.e., they have a progressive hearing loss. In the past, every time a patient’s hearing loss would get worse, s/he had to purchase a stronger set of hearing aids.
Today, we can increase the prescription in the hearing aids to accommodate for these changes in the patient’s hearing loss. However, the stronger we make the prescription, the greater the chance of feedback. Today’s industry-leading hearing aid feedback cancellation system allows us to increase patients’ prescriptions without feedback. This is very important and can extend the life of a set of hearing aids by years.