[adisinom]

If we're talking about damage to the cochlea:

- We don't really care if we further damage the hair cells that don't work.

- Outer hair cells amplify sounds. If they don't work, well, gotta amplify them some other way.

- A phenomenon called "recruitment" can cause loud sounds to be more painful for those with hearing loss. So you may not be able to amplify everything.

Hearing aids are a bit more sophisticated than an amplifier; they also act as an equalizer, compressor, feedback cancellation, and a bunch of other features of dubious benefit.

[jrace]

We do care and take great pains to prevent further damage to the hearing systems. All hearing aids will have a MPO (maximum power output) setting. All hearing tests (should)include a test to determine the maximum threshold of volume level.

Only in cases of sever to profound will a hearing device be programmed to exceed a safe normal hearing level.

Outer (inner actually) hair cells receive an input and there movement sends an electrical signal down the auditory nerve. In cases of hearing damage these hair cells are not as receptive and require a stronger "push" to move.

Dubious (in your opinion) or not, the other features are designed to improve the understanding of speech especially in noisy situations.

=============== Hearing aids cost a lot of money. no question. But they are not just devices pulled from the shelf and stuck in your ear. They require both initial settings (derived from hearing exams) and frequent follow ups as the user adjusts.

[40four]

Interesting, sounds like a lot of tech is packed into these tiny devices!