If you’ve ever worn a digital hearing aid, you’ll have realized by now that it’s much more complex than a tiny sound amplifier; hearing aids are delicate and highly engineered machines, miraculously compact and effective.
But how do they actually work?
The best answer is that hearing aids
involve three key pieces, all of which have to be finely-tuned.
The Digital Hearing Aid Microphone
All hearing aids include microphones. Originally, these microphones were quite simple, picking up ambient sound indiscriminately. Over time, however, engineers came to realize that during conversations, most hearing-impaired people attempt to focus on sounds coming from in front of them (the reason for the cupped, forward-tilted shape of our ears). Going back to the drawing board, they developed directional microphones capable of locating the source of the predominant sound in a room. Most hearing aids
now include omnidirectional (indiscriminate) microphones as well as directional microphones.
Digital Hearing Aids: the Digital Signal Processor
The Digital Signal Processor, or filter, of a hearing aid helps isolate important sounds from trivial ones, and allows the user to better control his or her device. Although hearing aid filters were once analog, since the invention of the first digital filter in 1984, digital filters have come to dominate the market. Now, filters may allow users to sync their hearing aids to their cell phones and to control the volume of their hearing aids remotely. Other crucial functions of the filter include white noise reduction and canceling interference from unrelated devices, like radios and non-digital TV sets.
Digital Hearing Aids: the Amplifier
The amplifier is the most straightforward part of a hearing aid. Just like the large amplifiers seen in movie theaters, malls, and garages everywhere, the amplifier of a digital hearing aid raises the volume of the sound signals it receives from the microphone once they have been
processed through the filter. The technology involved in designing amplifiers is relatively simple compared to the technology involved in designing the filter and microphone. However, because the amplifier uses the majority of the hearing aid’s battery power, engineering of the amplifier is a crucial part of hearing aid construction.
Audicus hearing aids are carefully designed and engineered to produce the best hearing experience possible.
by Veronica Mittnacht