BTE (Behind The Ear)
A Behind the ear (BTE) hearing aid is traditionally the most popular style. It is robust and easy to manage, and many of the newer models are quite small indeed. The hearing aid sits on top of your ear and contains a battery, microphones, microchip/amplifier and a speaker, along with wireless modules in some models. The sound is gathered, processed and reproduced in the hearing aid and is then transmitted to the ear canal via a tube.
For mild or moderate high frequency hearing losses, this tube is known as a slim tube, and is typically between 0.9 and 1.3mm diameter. Attached to the end, and sitting in the ear canal is a silicon tip, normally cone-shaped. This is a very discrete hearing aid option, and very comfortable, but is not suited for low frequency (below 1000Hz) or moderate - severe hearing losses, and can require some maintenance, as the tube is easily blocked with wax.
For more severe hearing losses, the tubing is increased to 3mm, and is attached to a custom made ear mould, which sits in the ear. This style is the most robust and secure, requiring little maintenance, but it can look a little bulky, and the mould must be custom made.