Hearing aids are marvels of small-scale sound amplification and computer processing. They consist of the same five core elements. These are the microphone, the receiver, the amplifier, the battery, and the microchip (or multiple microchips in some cases).
The microphone is what provides the unit with the incoming sound. The receiver is the device in your ear that emits the analog signal you actually hear. The amplifier ups the volume between the microphone and the receiver. The battery provides the power. And the microchip(s) are what make the modern hearing aid such a marvel.
Over the past decade or so, as Moore’s Law has really kicked in — the term refers to the arc of computer-processor speeds doubling every two years — the amount of computing power you can “stick in your ear” has become truly astounding.
A contemporary hearing aid takes the analog sound input of your environment (the microphone), converts it into digital form for processing and mixing and then converts it back into analog sound (the microchips), and then sends it into your ear (the amplifier and the receiver). All powered by a tiny battery.
The entire process is not unlike what a sound engineer does for performers. Input from the microphones, a “mix” at the soundboard, then amplified output through the monitors onstage.
And with the computing power now available, a wide range of things can be done to the raw incoming sound. Different mixes can be programmed for your hearing aid to be used in different hearing environments, feedback can be suppressed, sounds in certain frequencies inhibited or enhanced, and wireless connections to a wide variety of external devices established.
There’s a lot going on there. All powered by computer chips that pack the power of what used to be contained in an old desktop computer into something the size of your fingernail.