A hearing aid helps the ear to pick up sound, amplifies it and sends it into the ear canal. A hearing aid consists of a microphone that picks up sound waves and converts them into electrical signal, an amplifier, a loudspeaker (or receiver) that converts the amplified signals into sound and an ear mould or plastic tube that sends the sound into the ear canal. Hearing aids have a battery door where the battery is put in and you have the option of a volume control and/or a telecoil switch. A telecoil switch allows you to use your hearing aid on the telephone. Some hearing aids also have a program button where you can switch between different settings.
