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What you need to know about feedback cancellation

What You Need to Know About Feedback Cancellation

Published 09-08-2019
Last Updated 09-08-2019

Here are some of the ways hearing aids have evolved to eliminate excessive feedback.
Written by Annie L. Messmer, Doctor of Audiology

If you've ever worn hearing aids for an extended period of time, there is a decent chance you've experienced an occasional, high-pitched screeching noise at some point in your ears. More often than not, it is a sign that something may be wrong with your hearing aid.

The whole point of wearing hearing aids is to benefit from their amplification capabilities, but when the squeal persists it can quickly lead to frustration – making you want to shut the devices down or take them off entirely. Here’s how to identify audio feedback, be more cognizant of it, and take steps to prevent it in the future.

When does feedback happen?

Feedback happens when the sound that comes out of a hearing aid is picked up and reprocessed by the microphone, creating an audio feedback loop.

You can observe this at concert venues when the mic picks up the sound coming out from the speakers. This sound forms a feedback loop, creating a continuous cascade of reverberating sound. This is solved when microphones are not positioned in front of speakers.

You can also observe this at weddings when the individual giving a speech picks up the microphone and a high-pitched squeal reverberates throughout the banquet hall. Everyone immediately covers their ears. The same mechanism that happens between the microphone, amplifier, and sound waves occurs at a smaller scale in your hearing aids or personal sound amplification products (PSAPs).

Fun Fact

Did you know that Jimi Hendrix was one of the first musicians to take advantage of the feedback loop that would occur between electric guitar and amps? He discovered the distinct sound by accident – and it became a part of Hendrix’ musical style. He was able to create distinct sounds impossible with traditional playing techniques.

Various situations cause feedback:

  • Standing near a wall or solid surface
  • Hearing aid is set to high & too much volume is coming in at a certain frequency
  • Excessive earwax buildup
  • Dislodged microphones
  • Worn filter
  • Cracked or broken tubing (as in the case of BTE hearing aids)
  • Cracked hearing aid shell.

Tips to reduce feedback:

  • Adjust hearing aid volume to a lower threshold
  • Visit your audiologist or hearing aid dispenser to replace or repair your hearing aid shell
  • Be aware of the times you hear feedback, and have a conversation with your audiologist to customize your device
  • Have an audiologist fine-tune your hearing aid

Feedback cancellation

Unless you’re Jimi Hendrix using feedback to entertain a crowd, chances are you don’t want your hearing aid emitting a high-pitched sound. Luckily, manufacturers have devoted a lot of resources to try and fix this problem. With older hearing aid technology, the resulting whistle was a sure giveaway that someone was wearing a hearing aid.

Modern hearing aids come with feedback cancellation systems designed to decrease the chance of the feedback occurring. This lets you lean in for a hug with no embarrassing screech! If whistles, alarms, and incessant feedback loops are affecting your ability to hear, consider a modern device with this technology. 

Don't let outdated hearing aids keep you from enjoying life's little moments more often. Speak with someone about upgrading your hearing aids today. Call our friendly, helpful contact center to speak with a hearing consultant. You will learn more about the options available to you or your loved one who may be experiencing a hearing loss. Qualified candidates can receive a free hearing aid screening in their local area!

About the Author

Annie L. Messmer, Au.D.
Dr. Annie Messmer is a certified audiologist with a degree from Northwestern University and over 10 years of experience working with patients of all ages. She has also trained numerous hearing care professionals on audiology best practices and the latest hearing technology.