| abstract |
A magnetic induction hearing aid H where the microphone 20, the amplifying electronics 22, the battery 26 and a coil 28 are contained in a single housing 30 which is located deep in the ear canal 34. A magnet 32 is attached to portions of the middle ear by means of a malleus clip 60 or by implantation between the tympanic membrane 68 and the malleus 36. The magnet 32 is vibrated by interaction with the magnetic field produced by the coil 28. Two amplifier designs are disclosed for use with different levels of hearing loss. The magnet 32 can be coated with hydroxyapatite for permanent attachment to the body. The magnet 32 is coated with hydroxyapatite by an ion implantation process, a plasma spraying technique or a method of applying the hydroxyapatite while a precoating polymeric material has not fully solidified. |