How does a Hearing Aid work?

A hearing aid is a little computer. The Hearing aid consists of four basic components:

  1. A microphone to pick up the acoustic sounds around you and converts it into a digital signal, which it sends to the amplifier. The amplifier boosts the signals and then sends them to the ear through a speaker.

  2. An electronic circuit increases the volume human voices - minimizes background noise and sends this data to the receiver.

  3. A receiver/speaker changes the signal back into acoustic sound and sends it back into the ear. Then those impulses are then sent to the brain.

  4. And a battery to provide power to the hearing aid.

Hearing aids are primarily useful to people who have suffered sensorineural hearing loss from damage to the small sensory cells in the inner ear known as hair cells. The damage can be caused by disease, aging or injury from noise or drugs.
A hearing aid magnifies sound vibrations. Surviving hair cells detect the larger vibrations and convert them into signals that are sent to the brain.
There are limits to the amplification a hearing aid can provide. In addition, if the inner ear is too damaged, even large vibrations will not be converted into signals to the brain.