How does it work?
We receive sound in two ways, by air conduction via the ear canal, eardrum, and ossicles, and by bone conduction where the sound is transmitted directly through the jaw and skull bone bypassing the outer ear and the middle ear.
In most cases, those with a hearing loss will be fitted with traditional air conduction devices. These are placed inside the ear canal or behind the ear. However, some people are unable to benefit from this type of device.
The Baha system, which is based on bone conduction, utilises a titanium implant which is placed in the skull bone behind the ear. An abutment connects the sound processor with the implant in the bone. This creates direct (percutaneous) bone conduction. In contrast, traditional bone conductors connect indirectly to the bone through unbroken skin (transcutaneous) and work by exerting pressure against the skull.
Direct bone conduction provides a sound quality that is superior compared to traditional bone conductors as sound is not weakened by passing through the skin.
How it works
Sound Processor snaps on to abutment. Abutment is attached to the titanium implant placed in the bone.
Baha: direct bone conduction
1. Sound waves are received by the Baha® sound processor
2. Sound waves bypass middle ear function and are delivered directly to the working cochlea in both ears
Baha for SSD
For people with Single Sided Deafness (SSD), the Baha® system allows sound to be heard from the deaf side, provided that hearing is normal in the opposite ear. This is possible because the sound waves are transmitted through the skull bone to the functioning cochlea on the opposite side.
1. Sound waves are received by the Baha sound processor
2. Sound waves travel by bone conduction to the functioning cochlea on the opposite side
3. Sound is received by the functioning cochlea
Osseointegration
The Baha treatment involves a clinical procedure during which a small titanium implant is placed in the bone.
The implant bonds with the surrounding tissue – a process known as osseointegration. Osseointegration was a term coined by Professor Per-Ingvar Brånemark when he discovered the ability of living tissue to integrate with titanium.
Osseointegration has been described as a direct structural and functional connection between living bone and the surface of a load carrying implant.
During his original research, Prof. Brånemark found a way of using pure titanium as an anchoring unit and support for a variety of prosthetic reconstructions including what was then a new type of hearing device.
The long-term success of Baha rehabilitation is based on the fact that an active bond between tissue and implant is created at the molecular level. The implant is not only accepted but also incorporated within the bone.
A Bond Between Fixture And Bone
In the case of the Baha sound processor, the osseointegrated implant and abutment system not only provide secure retention for the sound processor itself but also the means by which the vibrations from the sound processor are transmitted via the bone to the cochlea; a process since known as direct bone conduction.