The Bone Anchored Hearing Aid or BAHA is an implantable device used for the treatment of hearing loss. BAHA is based on the principle of bone conduction. It works by a surgically implanted abutment that transmits sound through direct conduction through the bone to the cochlea. This process bypasses the external auditory canal and the middle ear.
BAHA comprises three components, i.e. a titanium fixture, a titanium abutment and the sound processor. During the surgery, the titanium fixture is embedded in the skull bone, while the abutment is exposed outside the skin. Healing typically takes around 2-6 months, after which the sound processor is attached. The device transmits vibrations to the external abutment. The abutment then vibrates the skull and the cochlea. These vibrations are what allows the individual to hear.
How does the BAHA system work?
There are three parts to the BAHA system:
- External Sound Processor– It is solely responsible for picking up sounds around you.
- Abutment or Magnet– It connects the processor to the implant and helps convert sounds to vibrations. These vibrations are then transferred through the abutment to the implant.
- Titanium Implant– This is surgically inserted into the mastoid bone and integrates into the bone over several months. This part transfers vibrations through the skull to the inner ear and cochlea.
Are you a good candidate for BAHA implantation?
The criteria to be considered for BAHA implantation are:
- Mild to moderate hearing loss
- Patients must have either mixed hearing loss or conductive hearing loss.
- Patients that cannot use hearing aids in the ear due to long-term infection and ear discharge.
- Children with abnormal or absent ears and external ear canals.
- Single-sided deafness
It is important to note that BAHA implants do not completely restore hearing or make every sound crystal clear. Their intended purpose is to make hearing loss more manageable by helping patients better discern speech and other sounds.
How is BAHA surgery performed?
General anaesthesia is used during the surgery, so the patient does not feel any pain. When the patient wakes up, the surgery is over.
Surgery is usually done in a single stage for adults. The external processor is not attached for around 3 months as time is given for the implant to integrate into the skull bone.
With children, surgery is typically performed in two stages. The first stage involves placing the titanium fixture in the bone. Around 6 months later, the second stage is performed, where the abutment is connected through the skin to the titanium fixture. Only after this is the external sound processor attached.