What is feedback in hearing aids?
When it comes to hearing aids, feedback is the phenomenon in which some of the sound which is amplified by the hearing aid leaks from the speaker end into the surrounding air and finds its way to the hearing aid’s microphone.
As the amplified sound reaches the microphone, it is once again processed by the hearing aid and hence, re-amplified. As this process repeats incessantly, the sound grows louder and louder due to continuous amplification and it reaches a point where it becomes a jarring, high-pitched whistling sound for the user.
This can be damaging for a hearing aid’s user, and result in noisy, echo-ey sound reception every now and then. One would expect a hearing aid device to be good at one thing if not many - and that is the quality of sound for the end user.
But surprisingly, many hearing aid manufacturers did not pay attention to this crucial quality-of-life feature in the past. With modern technology, however, Hear-Hi’s hearing aids and assistive listening devices are all equipped for what the industry calls ‘feedback cancellation’.
Feedback cancellation technology
Feedback cancellation technology in hearing aids comprises an adaptive filter that is used to simulate the feedback path. The output of this adaptive filter is then subtracted from the microphone signal to cancel the acoustic feedback picked up by the hearing aid’s microphone.
In simple terms, an opposite waveform is generated as compared to the feedback sound which cancels it out before the input signal is processed. It is a marvel of engineering as this process happens in real-time, thanks to dedicated computing power integrated into the hearing aids for the purpose.
With super-fast algorithms and raw computing power, modern hearing aids are now able to analyze feedback inputs and cancel them out completely, thus providing hearing aid wearers with a more comfortable and realistic listening experience.
What type of hearing aids have the best sound quality?
If you’re looking for excellent sound quality in your hearing aids, going with the ones that feature some form of feedback cancellation system is the only way. If your assistive listening device lacks this technology, you will experience highly annoying sounds such as high-pitched screeches, echoes, and distortion in everyday listening.
Nowadays, hearing aid manufacturers achieve a high level of feedback cancellation by employing several techniques simultaneously.
Tight speaker seal
The feedback problem takes birth from the fact that some amplified sound manages to escape from a hearing aid from the speaker end. However, if the seal between the wearer’s ear and the hearing aid’s speaker is tight enough, the chances of sound leaking from there reduce drastically.
Advanced audio processing algorithms
Audio processing has always been more about software than hardware. With super-modern AI algorithms, hearing aids can identify feedback signals even before they reach the microphone. These algorithms tell the device to actively generate a canceling waveform which cancels the feedback sound as it leaves the speaker.
Powerful computing hardware
If your hearing aid has a powerful computing chip at its core, you can expect top-quality sound delivery. Modern chips are equally efficient, which means all this performance does not come at the cost of battery life.
It is important to keep in mind that the hearing aid you are about to buy must feature feedback cancellation so that you do not have to experience unwanted loud sounds when you start daily driving them. Quality manufacturers like Hear-Hi promise the best quality digital hearing aids and assistive listening devices so that you can listen better.
It is better to not cheap out initially when buying hearing aids because cheap hearing aids lack many important features and make you pay more later down the road. Investing in the proper product can save you a lot of trouble.
Frequently Asked Questions
What are the most important features of hearing aids?
Noise and feedback cancellation, good quality microphones, tight speaker seals, and advanced hardware-software integration are crucial when it comes to promising a high-quality performance from a hearing aid.
Why is feedback cancellation so important in hearing aids?
Feedback in a hearing aid can seriously deteriorate a user’s experience due to extremely loud, high-pitched whistling sounds. Users who are already susceptible to hearing damage must avoid such hearing aids and get the ones with feedback cancellation in them.
How does the feedback manager work in hearing aids?
The feedback manager continuously monitors the part of the sound signal that returns to the hearing aid microphones. The purpose of the feedback manager is to remove this unwanted feedback part of the input signal before it is re-amplified incessantly, effectively creating loud whistling sounds.