Patients that are in the process of being fitted for a hearing aid to help them hear quiet sounds frequently ask what the hearing aid is going to do with sounds which are still excessively loud. Fortunately there is a reassuring answer to this particular question.
In short, modern hearing aids which are properly fitted and adjusted are designed to avoid amplifying sounds that are already very loud. The important phrase in bold type is why you should seek the assistance of a hearing aid specialist.
A longer answer to the same question requires an explanation of hearing aids themselves, and the way that 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 hearing aids are programmable, which means that not only can the maximum volume permitted be adjusted to suit your individual tastes, the actual qualities of the sounds can also be adjusted. 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. This preference can be reversed, of course, if you suffer from primarily low-frequency hearing loss.
The newest digital hearing aids can also filter sounds to make them easier for you to understand. 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. The hearing aids can also be adjusted to dynamically compensate for differences in volume; if the speaker or music you are listening to starts softly but then increases and becomes too loud, the hearing aid can compensate for this. 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. But properly fitted and properly programmed, your hearing aid should cover most of the situations you are likely to find yourself in.