What is a hearing aid?

Hearing aids are medical devices, Class II. It is an aid used by the hearing impaired. It is used to compensate for hearing damage, the resulting defects. And then improve with people. Drawing the ability to communicate tools. Equipment devices and instruments, etc. Broadly speaking, all sorts of devices that effectively transmit sound into the ear can be viewed as hearing aids. In a narrower sense. A hearing aid is a. Electroacoustic amplifier. Through it to amplify the sound so that deaf people hear the original hearing is not clear, can not hear the sound, this device is a hearing aid. He has divided into linear and non-linear hearing aids. The linear ones are analog. Non-linear for the digital base.