Different types of hearing aids:

Behind-the-ear:

Behind-the-ear hearing aids, also referred to as a BTE, the amplifier, microphone, and receiver are housed in a shell that fits behind the ear.  A custom earmold is worn in the ear and connected to the hearing aid by a clear plastic tube.  Behind the ear hearing aids can hold more circuitry than other style hearing aids because of its large size shell. BTEs are very durable and can be fitted for a wide range of hearing losses.

In-the-ear:

In in-the-ear hearing aids, also called an ITE, the circuitry is built and housed into a custom earmold that fills a majority of the visible portion of the ear.  In-the-ear hearing aids are ideal for people with limited dexterity because of their size and easy-to-use controls. ITEs are best for individuals with mild to moderately severe hearing losses.

In-the-canal:

In-the-canal hearing aids, also referred to as ITC, are smaller than in-the-ear (ITE) hearing aids.  ITC hearing aids are partially visible in the outer ear.  This type of hearing aid is best for mild to moderate losses.

Completely-in-the-canal:

Completely-in-the-canal or CIC hearing aids are custom-fit devices that fit all the way in the ear canal.  They are barely visible therefore cosmetically appealing.  These tiny hearing aids are best suited for individuals with a mild to moderate hearing loss.  Some hearing aid wearers with narrow ear canals may not be able to wear CIC style hearing aids.

Mini BTE

Mini BTEs are smaller and less noticeable than traditional BTEs.  Mini BTE's are similar to traditional behind-the-ear hearing aids in that the shell fits behind the ear. Typically a thin acoustic micro poly tube or transmission wire (in receiver-in-canal hearing aids) connects the shell to a custom earmold or dome shaped ear bud.