It is a small amplifying device which fits on the ear used by a hearing impaired persons.
Analog. Analog Programmable, Digital Trimmer Controlled, Digital Programmable.
NAL-NL1, PROGO -II, Bernafit, XcelFit, ConnexFit, Stat etc as per manufacturer fitting algorithms it may vary.
Body Worn , Behind The Ear or BTE. Receiver In Canal or RIC. In The Canal or ITC. Completely in Canal or CIC. Invisible in Canal or IIC. Spectacle. Bone Vibrator etc.
Common color is beige, beside that black, red, golden, dark brown etc color hearing aids are available now.
From 1 channel to 48 channels aids are available in the market. Bernafon own Channel Free technology aids which works on principle of channel free technology.
Normally hearing aid have single microphone. Now two to four numbers of microphones are available on selected models.
Depending on models, number of channels. number of microphone. multipurpose features. gain and fitting ranges of aids. And others are related to set hearing aid price for individual user. Contact hearing care professional for this matter or get details at http://www.calcuttahearing.com or at http://www.shrobonee.com
Various features like water resistance. dust proof. noise free. directional microphone. nano coating IP rated hearing aid etc are available in the market.