A common patient question is whether their hearing aid will increase sounds which can be already excessively loud for them, making those sounds louder still. This is a normal question, one for which there is thankfully a reassuring answer.
Put simply, as long as they’re correctly fitted and adjusted today’s hearing aids are made so that they won’t take loud sounds and make them louder still, possibly harming the user’s ears. The phrase in bold type is the important part, and the reason why you should seek professional help with choosing 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. An example might be that we program your hearing aid to amplify high-frequency sounds and reduce the volume of lower-frequency sounds if you suffer from primarily high-frequency hearing loss. This preference can be reversed, of course, if you suffer from primarily low-frequency hearing loss.
In addition, modern digital hearing aids are able to filter the sound to make it more understandable. For example, if foreground voices are obscured by background noise, the hearing aid can detect the noise and suppress it or lower its volume, amplifying only the voices. These digital hearing aids can even adjust dynamically to volume fluctuations such as a musician beginning a song very softly and then increasing the volume.Directional microphones also allow the hearing aid wearer to hear faint sounds coming from the direction they are facing, while suppressing noisier sounds coming from behind or to either side.
Be aware that hearing aids do not protect the ear the way that ear plugs are designed to do. Loud sounds like chainsaws or overly amplified rock concerts, will therefore still be able to cause noise-induced hearing loss. But in most situations your properly fitted and programmed hearing aid should handle most of the range of sounds you’re likely to encounter.