What is feedback in hearing aids?

What is feedback in hearing aids?

Some of the negative stigma surrounding hearing aids and their use is based on the fact that hearing aids were once bulky items that would squeal or squeak in the wearer’s ears. This squeaking or whistling is known as feedback.
Fortunately, today’s technology is much more appealing cosmetically and significantly more sophisticated in terms of managing feedback than prior generations of hearing devices.

What is feedback?

Acoustic feedback occurs when the amplified sound from a receiver re-enters the amplification system through the microphone and is amplified again. While most feedback tends to sound like a whistling, the actual sound can vary from a hum to a piercing screech.

Can feedback be managed?

Yes! Most current hearing aid technology offers a feedback management system that makes whistling a thing of the past. The system is typically run during the initial fitting process or any time a modification or repair is complete.

Starkey Hearing Technologies has the industry’s leading feedback management system. They use a complex system of phase cancellation to identify possible situations where feedback may occur, and create a signal opposite in phase to eliminate that feedback. (“Phase” refers to the up and down movement of a sound wave.)
In addition to the feedback management systems present in today’s technology, your hearing professional can also make changes to your hearing aids’ output and gain (amplification), which can be beneficial in the elimination and prevention of feedback.
However, there are situations in which feedback may occur for reasons outside of the device itself.

Possible causes of feedback

1) Hearing aid fit/seating
When a custom hearing aid or the earmold/dome does not create a proper seal within the ear canal, the sound may be able to leak out and become re-amplified. In this situation, a different acoustic option may be most the appropriate solution.
Other times, the receiver may be misaligned with the path of the ear canal, causing the sound to hit the wall of the ear canal. This creates a potential for feedback. In this case, a remake or deeper earmold impression may be the most appropriate fix.

2) Earwax
Earwax (cerumen) can also create a potential for feedback. If the sound is unable to effectively travel to the eardrum because it’s blocked by earwax, it may bounce off the cerumen and be re-amplified. It is important to have regular earwax management in place if one is prone to wax build-up when using amplification.

Feedback is no longer an issue

Today’s hearing aids have come a long way from the hearing aids your parents or grandparents wore. The ability to eliminate feedback is just one of many benefits that Starkey hearing aids now provide. Experience these benefits for yourself by asking your hearing professional for a demonstration of the latest technology.

Source: https://www.starkey.com/blog/2017/09/Feedback-in-hearing-aids