There are four basic configurations of hearing aids: behind-the-ear (BTE), in-the-ear (ITE), in-the-canal (ITC), and completely-in-the-canal (CIC).
Behind-the-ear (BTE) aids are supported by an earhook and rest substantially behind the ear. The microphone is usually positioned at the apex of the ear. A receiver in the body of the aid produces sound that travels through a tube within the hook. In turn, this connects to a flexible tube terminated in an ear mold at the ear canal. BTE aids frequently have a telecoil which can be connected in place of the microphone by manual actuation of a miniature switch. The telecoil picks up magnetic flux from the telephone handset receiver. This is necessary because the microphone of the BTE aid is not in a position to pick up the acoustic output of the handset receiver.
In-the-ear (ITE) aids partially fill the concha, or bowl, of the ear. A receiver inside is ported directly to the ear canal. ITE aids frequently incorporate a telecoil, even though the microphone of the ITE aid is in the acoustic path of the telephone handset receiver. There is a tendency for the ITE aid to feedback (howl) when the ear is covered by the telephone receiver; this feedback is avoided when the telecoil pickup is used.
In-the-canal (ITC) aids are small enough to be contained predominately within the ear canal. Due to size constraints, they may not contain telecoils.
Completely-in-the-canal (CIC) aids fit completely in the canal portion of the ear. Due to their very small size, they may not contain telecoils.
Hearing Aid Compatible Poly Headset Models: