Anatomy of a Hearing Aid
Every electrical hearing aid has three parts; a microphone, an amplifier and a receiver.
These three functions have to be housed in a small capsule called the hearing aid.
This is an expensive task and can explain why people are often amazed and disappointed by the price range of hearing aids. They make the mistake of comparing the price of a hearing aid to that of a pair of glasses, which have mass-produced frames and lenses, which serve their purpose.
However, the digital hearing aid, which is so small as to be practically invisible, could be compared to a contact lens.
Everybody’s hearing loss is different and the hearing aid has to match the way the sounds are lost in passing from the outer ear to the auditory nerve. This demands a whole range of small and expensive equipment.
This collects the sound and converts it into electrical impulses. These reproduce the rise and fall of pitch of the sound (high or low) and the intensity (loudness measured in decibels).
This modulates the electrical impulses, makes sounds louder or quieter. It can have an integrated circuit with up to 30 transistors or a combination of circuits. The digital aid uses the efficient micro-chip.
It converts the amplified signal into sounds and feeds them into the ear.
Hearing aids get their power from tiny batteries.