How do hearing aids work?
Information for kids: The information on this page is for adults. If you want a child-friendly way to explain hearing aids, check out our comic Ali Gets Hearing Aids.
Hearing aids typically work by amplifying sounds and making them clearer. Quieter sounds are amplified more than the louder ones so that they always stay within the child’s comfortable range. A hearing aid consists of a microphone, amplifier and receiver. The microphone picks up the sounds around the wearer and converts them into electrical signals which are then processed and amplified. The electrical signals are then converted back to sound and the receiver sends the amplified sounds into the ear through the earmould.
There are also hearing aids that work by vibration, known as bone conduction hearing aids. They change the sound from an acoustic (sound) signal into a mechanical signal (vibration). The receiver is a small vibrating pad that is held behind the ear by a soft or metal headband and allows sound to be conducted through the skull bone rather than through the outer and middle ear.
Your audiologist will program the hearing aids to match your child’s deafness before testing them in your child’s ear to make sure that the signal (or frequency response) coming from the hearing aid matches as closely as possible.
Features of behind-the-ear hearing aids
Most hearing aids are turned on and off by opening and closing the battery drawer.
Hearing aids often have several different listening programmes for different situations (for example, in normal and noisy listening situations and when listening to music).
When children are very young it’s likely that they’ll only have one programme and there won’t be any controls or buttons to worry about. As they get older and are able to control the hearing aids themselves, programmes can be introduced.
If the hearing aids do have controls you may have a volume control, programme button or function switch.
Volume control – many digital hearing aids don’t have a volume control or have a very limited one. This is because the hearing aid can adjust itself automatically to the listening environment.
Programme button – there may be a separate button for switching between programmes or it may be part of the function switch (see below).
Your audiologist will explain which programmes there are and in which situations they should be used.
Function switch – used to turn the hearing aid on and off and may be used to switch between listening programmes.
A hearing aid will have a microphone that can be programmed to be omnidirectional (pick up sounds from a wide area all around the wearer) or directional (give priority to sounds coming from directly in front of the wearer).
Most hearing aids will be programmed so that they automatically switch between omnidirectional and directional settings depending on the listening environment.
Small elbows (also called tone hooks) may be used with very young children or those with very small ears. The smaller elbow makes sure that the hearing aid will fit snugly on the ear and sit more securely when the child is playing.
A child-safe battery door lock is a safety feature which stops children from being able to open the battery compartment and swallow the battery. The lock is usually secured with a small screwdriver.
Some hearing aids will have an LED visual status indicator which when glowing, indicates that the hearing aid is working, when there may be a fault, or when the battery needs changing.