VATHLT2390 - Hearing aid dispensers: What is a hearing aid?
A hearing aid basically consists of a microphone to pick up the sound, an amplifier to make the sound louder, an earphone to pass the sound into the ear, and an ear mould which fits into the ear. Hearing aids range from hearing trumpets (which are still occasionally used) to very sophisticated computer controlled devices and can be body-worn, behind-the-ear, built into spectacle frames, or (most popular) discreet in-the-ear models.