Speech in Noise part 3: Why is Noise a Problem for Hearing Aids?

Posted by Dr Andrew Simpson on Nov 14, 2020 6:54:25 PM

Noise is a problem for hearing. Noise makes it hard to hear people talking to you. Noise induced hearing loss is very common. The World Health Organisation provides guidance on noise exposure risk that is quite unambiguous: listening to high sound levels for long periods of time is likely to result in permanent hearing loss.

This is a very difficult situation for hearing loss - the basic purpose of a hearing aid is to amplify sound to high levels so you can hear - and this often means noise.

To put this conundrum in perspective, consider a typical hearing aid fitted with a modest prescription gain of 40dB across the frequency range - in principle this is a volume boost of 40dB over your environmental noise exposure. If there is no noise reduction at all in the hearing aid and no limiting this means that sitting in a cafe with a (typical) background noise level of 75dB will result in a sound level at your ear of 75+40dB = 115dB of background noise.

According to the World Health Organisation, that provides a safe exposure time of less than one minute per day.

So, a hearing device driven by an AI that can allow you to hear speech clearly whilst reducing 75dB of background noise to absolute silence would extend your safe listening time considerably by WHO standards.

At Chatable, we are developing the world’s first real-time zero-latency AI for speech in noise that can run on-device and that can reduce 75dB of background noise exposure into absolute silence for a safer device.

Keep an eye out for updates.