Bone conduction hearing devices
Why would my child need a bone conduction hearing device?
The inner ear receives sound vibrations in two different ways; through the ear canal, ear drum and middle ear (air conduction) and through the skull bone (bone conduction). Conventional hearing aids work using air conduction but for a number of reasons some deaf children can’t wear conventional hearing aids. A bone conduction hearing device works better for them because of the type of deafness that they have.
How do bone conduction hearing devices work?
A bone conduction hearing device (also known commonly as a BAHA) works by transmitting sound vibrations through the bone. The sound processor converts the sound picked up by its microphone into vibrations. The sound processor then transmits the vibrations through the bones of the skull to the cochlear of the inner ear. The inner ear then converts these (sound) vibrations into electrical signals that the brain interprets as sound. A bone conduction hearing device therefore allows a child to hear sounds that can’t pass through the ear in the usual way, which is through the outer and middle ear.
There are three types of bone conduction hearing devices:
- Bone conduction hearing implants (abutment through the skin, surgically implanted).
- Bone conduction hearing implants (magnet under the skin, surgically implanted).
- Bone conduction hearing aids (soft headband, non-surgical).
A bone conduction hearing implant is used permanently following one or two surgical procedures to fit part of the device.
A bone conduction hearing aid or the sound processor of a bone conduction hearing implant worn on a headband can both be used by children on a temporary basis if their hearing is expected to improve with time. They can also be used permanently by children when it is not advisable for them to have surgery.
A BCHD may be an option if your child has a conductive deafness and doesn’t benefit from wearing a conventional hearing aid.
BCHDs are suitable for children who may have permanent or long-standing conductive deafness such as:
- Microtia (malformation of the external part of the ear), atresia (absence of the ear canal), which means they can’t wear a conventional hearing aids.
- Congenital syndromes, for example, Down’s syndrome, Treacher Collins and Goldenhar
- Middle ear disease
- Mixed deafness combination of Sensorineural Hearing Loss (SNHL) and Conductive Hearing Loss (CHL)
- Permanent deafness affecting one ear only (known as unilateral or single sided deafness)
A bone conduction hearing aid may also be considered for children with:
- perforations of the eardrum
- glue ear
- persistent ear infection (discharging ears) that prevents a child from wearing an ear mould in their ear and therefore can’t use an Air Conduction Hearing Aid (ACHA) consistently
Your local audiology service should provide a comprehensive assessment of your child’s hearing, including bone conduction testing. Depending on the results, your child will be fitted with a suitable hearing aid for at least four weeks. If your child finds the hearing aid doesn’t help and they meet the criteria set by the BCHI manufacturers, they will be given the option to be referred to the Hearing Implant Service for further assessment for a BCHI.
‘Local services’ are those based in your local hospital, education department and social services team. It’s really important for the professionals in these local services to work with the Hearing Implant Service so that everyone understands the needs of each individual child and can provide day-to-day support.
Having a BCHI will mean lifelong care and commitment by yourself, your child, the NHS, and the Hearing Implant Service. It’s important that you have all the information you need to make an informed decision.
As part of the assessment, the Hearing Implant Service will provide information about support groups (see below) and give you the opportunity to meet another family and child who:
- is the same age and wears a BCHI
- was the same age and at the same development stage as your child when implanted
- has the same level of deafness as your child
Meeting other families will give you and your child the chance to talk to them about their experiences of BCHIs as well as the opportunity to ask questions.
This meeting will be very valuable in answering your questions and helping you to decide whether you think a BCHI is right for your child.
You may be given information for the BAHA support groups, voluntary services and blog: