What are Bone Anchored Hearing Aids?
Bone anchored hearing aids conduct sound directly through the bone. This article explains in detail what bone-anchored hearing aids are, how they work, who may benefit from getting such a device, and how to access the assessment process for getting a bone-anchored hearing aid. We’ll also discuss different reasons for considering a bone-anchored hearing aid.
Different types of hearing loss may benefit from a bone-anchored hearing aid. Pending the proper assessment from an Audiologist and ENT (Ear, Nose, and Throat) Implant Surgeon, a bone-anchored hearing aid may be the right choice for you.
Bone Conduction Hearing Devices
Bone anchored hearing aids have been around for at least 40 years and were invented in Sweden. There are different types of bone-anchored hearing aids such as the BAHA (a Cochlear product) and Bonebridge (a Medel product).
How do they work?
Bone anchored hearing aids are an implantable hearing device that works by transmitting sound to the inner ear (cochlea) by mechanical skull vibration.
Normal hearing has a component of bone conduction hearing. A bone-anchored hearing aid is bypassing the outer and middle ear hearing systems and sending an auditory signal directly to the cochlea, in order to improve your hearing loss.
BAHA versus Bonebridge Hearing Aids
BAHA (bone anchored hearing aids) is a Cochlear company product and consists of a titanium implant that is placed in the bone behind the ear with the implant transferring the sound vibrations directly to the cochlea via bone conduction. The implant is directly anchored by the formation of bony tissue around the implant in a process called osseointegration.
The BAHA product has two different ways of delivering sound being percutaneous and transcutaneous. The percutaneous system involves a direct link between the bone and the outside with a titanium screw (abutment) that protrudes through the skin. The bone-anchored sound processor then attaches to the screw.
It does however require good hygiene to avoid the risk of infection around the abutment area. The transcutaneous system involves a magnet being placed under the skin so that the sound processor can attach to that through magnetic attraction thereby maintaining intact skin with a lower risk of infection. It can be a more discreet and aesthetically appealing option.
The BAHA products do provide for coverage of all types of suitable hearing losses by allowing the transcutaneous option to be changed to a percutaneous option if the hearing loss deteriorates to a degree that requires maximum gain and performance.
BAHA also have non-surgical options (soft band and SoundArc) which allow for trialling bone conduction temporarily (e.g. pre-surgery to assess benefit), or being able to wear a bone-anchored hearing aid permanently without having it implanted. They both work by having a band device which sits on the head and has the bone-anchored sound processor attached to it for placement against the bone just behind and slightly above the ear.
Bonebridge differs in that it is only a transcutaneous system with the implanted device using magnetic attraction to communicate with the external sound processor.
The sound processor is slimmer and more cosmetically appealing than the BAHA and just sits directly on the scalp, compared to the bulkier BAHA which consists of the sound processor than a magnet plate with a foam base.
Bone-anchored hearing aid surgery
All bone-anchored hearing aids require surgery to implant the internal device onto the mastoid bone of the skull to enable bone conduction transmission of sound. This is typically minimally invasive surgery making it a straight forward surgical procedure. There is a 4 to 8 week healing time which is required between surgery and fitting of the external sound processor.
Your Audiologist will make an appointment for you to come to your local Attune hearing clinic for fitting of the sound processor, and assist you with information on how to use and look after your bone-anchored hearing device.
Non-surgical options to bone-anchored hearing aids
Some people are unable to have the surgical option to implant the bone-anchored hearing device. This may be because they are an infant or young child and their skull thickness is not enough to support the implant.
Other reasons are a lack of manual dexterity to manage the device, or not being ready for surgery despite experiencing difficulties due to hearing loss. Adults may have a contraindication to having the implantable device if they work in areas of high concern e.g. strong magnetic fields. An Audiologist can assist you with this non-surgical option.
Are you a suitable candidate?
It is important to get your hearing loss assessed by an Audiologist who will do a diagnostic hearing test to determine whether your hearing loss meets the criteria for a bone-anchored hearing device.
Your Audiologist will then ask your GP to refer you to an ENT Implant Surgeon who will discuss in more detail the surgical procedure for getting a bone-anchored hearing aid and assess your medical suitability.
There are different types of hearing loss that may benefit from a bone-anchored hearing aid.
- Conductive hearing losses have a problem with the conduction of sound via mechanical means through the outer and middle ear systems to the cochlea (inner ear). This may be caused by anatomical deformities and middle ear infections that make wearing conventional hearing aids impossible.
- Mixed hearing losses have a conductive part and a sensorineural part too that involves a problem with the inner ear (cochlea) and the hearing nerve. This means that sound is not transmitted normally to the auditory nerve from the cochlea and beyond and can be due to age-related hearing loss or noise-induced hearing loss.
- Single-sided deafness means that one ear has normal hearing and the other ear has a hearing loss. This could be caused by trauma or sudden hearing loss due to an infection which affects only one ear.
The assessment process for bone-anchored hearing aids involves a medical referral to an ENT Implant Surgeon and audiological assessment by your Attune Audiologist.
This may involve:
- Discussing your hearing loss
- How it impacts on your life
- Why conventional in-the-ear hearing aids are not suitable
- Setting up a trial of a bone-anchored hearing aid
- Doing aided speech testing
- Reviewing your motivations and expectations for considering this type of surgery
A CT scan will be required to review your middle ear system.
Funding options for bone-anchored hearing aids
There are several funding options available depending on your circumstances and eligibility for each funding option.
Private health funds
If you have private health fund cover then you need to check:
- What level of cover you have (e.g. gold or silver hospital cover)
- Have you had the policy for more than 12 months?
- Are you eligible for bone-anchored hearing aid coverage?
You do have the option to upgrade your cover and wait for the 12 months, or join a fund and wait for 12 months if not already a member.
If you have DVA (Department of Veterans) cover (Gold or White card for hearing loss) then you may be covered for all expenses deemed medically necessary to improve your hearing loss.
In relation to bone-anchored hearing aids, DVA may approve funding to cover the costs of the surgery and the implant (internal/external) devices. If you are eligible for Hearing Australia (a government agency) then they will fund the bone-anchored hearing aid sound processor, ongoing maintenance, consumables, and audiological services.
Public funding options
Public funding is limited and on a state-based system so the best person to advise you of what level of public funding may be available is your ENT Implant Surgeon. You can choose to self-fund a bone-anchored hearing aid and would need to get quotes for all associated costs from the product company (e.g. Cochlear or MEDEL), the implant surgeon, the hospital, and your Audiologist.
Non-surgical bone-anchored hearing aid funding options can be through a private health fund (ex-gratia request), Hearing Australia (eligibility criteria applies), DVA, National Disability Insurance Scheme (NDIS – eligibility criteria applies), or self-funding.
These avenues are the same for obtaining funding for replacements/upgrades of your bone-anchored sound processor which will over time given to wear and tear need to be changed. It is always advisable to protect your bone anchored sound processor against loss and breakage by taking out the appropriate insurance cover.
Ongoing care and maintenance
It is essential that after being fitted with a bone-anchored hearing device that you continue to have follow-up appointments with your Audiologist. Initially, these may be at 2 weeks, 6 weeks, 3 months, and then 12 months post your initial fitting of the bone-anchored hearing aid.
Each appointment allows the Audiologist to check your surgery site and magnet site for any signs of skin breakdown would lead to infection, to discuss how you are managing the device, review how well you are hearing with the device, check for any device wear and tear, and answer any concerns and queries that you may have in relation to the bone-anchored hearing aid.
Your Audiologist will also check your hearing periodically (at least once a year or sooner if you feel that your hearing loss has changed) to be able to fine-tune the bone-anchored hearing aid for your specific hearing needs.
In a Nutshell
If you can’t tolerate conventional hearing aids or the hearing aid currently used is limited by medical issues then a bone-anchored hearing aid may be the best solution for you.
Which device or product provides the optimal outcome for you will depend on a number of factors such as the type of pathology and hearing loss, your lifestyle, skin condition, general health, cognition, environment and personal preferences.
Assessing your suitability for a bone-anchored hearing aid is as easy as asking your Audiologist to do a diagnostic hearing test and then getting a referral from your GP to an ENT Implant Surgeon.
You will always have the support of your Attune Audiologist throughout the assessment process and post-surgery for ongoing care and maintenance of your hearing and the bone-anchored hearing device.
Get in touch with us today to schedule a comprehensive hearing assessment with Australia’s only accredited hearing healthcare provider and start your journey to better hearing health. We can’t wait to support you along the way.