A question often asked by patients is whether their new hearing aid will increase sounds which can be already too loud for them, making those sounds louder still. This is a logical question, one for which there is thankfully a reassuring answer.
In short, modern hearing aids which are correctly fitted and adjusted are designed to avoid amplifying sounds that are already too loud. We can’t overemphasize how important the phrase in bold is; this is the reason you should have professional help with selecting and fitting your hearing aids.
The more complex answer has to do with the nature of modern digital hearing aids themselves, and how they work. Basically, they pick up sounds and transform them into digital information, which is then processed by the microchip in the hearing aid in many different ways before being routed to your ears. These digital hearing aids can be programmed, allowing audiologists to not only set a maximum volume that suits you, but to transform the nature of the sounds you hear. If you have primarily high-frequency hearing loss, for example, we might program the hearing aid to amplify those sounds while reducing the volume of lower-frequency sounds. On the other hand, if you suffer from low-frequency hearing loss, the hearing aid settings would be reversed.
In addition, modern digital hearing aids are able to filter the sound to make it more understandable. Background noise can be detected and reduced in volume, while voices in the foreground can be detected and amplified so you can hear them more easily. If volume levels change – for example if music starts at a low volume but then becomes too loud – the hearing aid can dynamically compensate for it. This process is aided by directional microphones that can detect where sounds are coming from and thus reduce the volume of background noise coming from behind or to the sides while increasing the volume of sounds coming from in front of you.
Be aware that hearing aids do not protect the ear the way that ear plugs are designed to do. Noise-induced hearing loss can still be caused by loud sounds such as chainsaws or overly amplified rock concerts. However, the most common sounds you encounter should be handled by your properly fitted and programmed hearing aids.