Hearing Aid Technology
Hearing aids have come a long way since the days of analog technology.
Hearing Aid Information
Digital hearing aids do four basic things:
- Sound Processing: This is the basic function of a hearing aid. The sound is modified and amplified to make speech clearer to the damaged ear. One critical element in sound processing is harmonic distortion. Any time we process sound electronically, we introduce some level of distortion of sound. Today’s best hearing aids produce about a half a percent, down from 3-5 percent only abut five years ago.
- Noise Suppression: The processors in the best hearing aids can identify steady-state background noise, like fans, machinery, road noise and the hubbub of a crowd. The noise is then turned down without affecting speech. The purpose isn’t to control noise, but rather to enhance speech intelligibility.
- Directional Microphones: This technology uses two microphones to cut out sounds that come from the back and sides, which is very useful in restaurants, movies, church or any other situation when you only care to hear what is in front of you.
- Feedback Control: Feedback is that nasty whistling sound hearing aids can make. Feedback makes hearing more difficult and is annoying to everyone. It’s usually caused by too much amplification of a high-pitched sound. New computer algorithms can reduce or even eliminate this common problem.
Virtually all hearing aid batteries sold today are Zinc-Air. This means that they contain zinc and "burn" air to produce a current. Zinc-Air batteries should always be stored at room temperature. Never put hearing aid batteries in the refrigerator, as this will ruin them. From the date of the manufacturer, most batteries will store well for up to four years.
Batteries come in four standard sizes that are numbered and color-coded. Size 10 batteries are coded yellow, size 312 are coded brown, size 13 are coded orange, and size 675 are coded blue.