Hearing Aid is an electronic amplifying device to make sounds audible to the individual with a hearing loss. Hearing loss is one of the oldest of the known disabilities. Attempts to amplify sound go back several centuries.
Hearing Aid definition:
A hearing aid is an ultra-miniature electro-acoustical device that is always too large. It must amplify sound a million times, but bring in no noise. It must operate, without failure, in a sea of perspiration, a cloud of talcum powder, or both. It is a product that one puts off buying for ten years after he needs it, but cannot do without it for thirty minutes when it has to be serviced.
Samuel F.Lybarger (mod. W.Staab)
Hearing aids past and present have the same basic function: to increase the volume of sound for the impaired user. Before electricity, the only way to achieve this goal was to filter out other noise by directing the desired sound straight into the ear with some kind of tube or trumpet.
The first transistor hearing aid was introduced in 1953. With the development of the transistor, the aids were able to become smaller and more powerful. The use of microchips for programming hearing aids was introduced in 1985.
Today's modern electronic hearing aids convert sound pressure waves into electricity by a microphone. The electric impulses are then amplified through controlled electronic circuitry. The amplified electric impulses are then reconverted by a receiver to pressure waves at a much more intense level to be presented to the impaired ear.
Different styles of modern hearing aids:
