There are different types of hearing aids, mainly Behind-the-ear, In-the-ear and Canal types. These types are different in sizes, shapes and power.
Behind-the-ear is also known as BTE. BTE consist of two parts, one hard plastic case worn behind the ear and another soft earmold that fits inside the outer ear. The hard plastic case contains the electronics parts and also receive the sound from the surroundings. Inside the electronics, it does all the analysis and conversion. Then it will produced the amplified sound to the earmold to the ear. BTE can be used by all people to people with extreme earing problems.
In-the-ear is known as ITE in short. As meant by the name, this type of hearing aids fits completely inside the outer ear. Usually this type of hearing aids are for middle range hearing loss. This type contains all the electroncis inside the hard plastic case. This type does the receiving, processing and output of the sound to the ear. This hearing aid is less visible than the Behind-the-ear type. As it is inside the outer ear, it is convenient especially talking over a phone. However this type may not be suitable for kids as their ears will grow and the shape will change. As such, the ITE will not fit well into the outer ear.
Lastly the smallest of all is the Canal aid. This type is the smallest and almost invisible. Usually for mild hearing loss only. This is due to the limited size and power that it can produce. Also because of the size, there is no much space for bigger batteries and complex components. On the other end, canal aid is the most esthetics among the rest.