Bone Anchored Hearing Aids
What is a Bone Anchored Hearing Aid (Baha)?
A Baha system is a surgically implantable medical device for treatment of hearing loss that works through direct bone conduction. People with certain types of hearing loss caused by damage or blockage to the outer or middle ear (conductive or mixed hearing loss), or those with single-sided deafness, are candidates for a Baha device. These patients typically receive little or no benefit from traditional hearing aids.
How does a Baha work?
A Baha system uses bone conduction to bypass the damaged parts of the outer and middle ear and directly stimulate the inner ear (cochlea). Thus, for people with conductive or mixed hearing loss, sound travels around the problem area. For those people with single-sided deafness, the device is placed on the same side of the head as the deaf ear. In this case, the sound travels across the skull and stimulates the opposite ear, thus allowing the person to understand someone who is speaking on their deaf side.
A Baha system consists of three parts:
- A digital sound processor which is worn behind the ear. The sound processor picks up sounds in the environment, then amplifies them and converts them to sound vibrations.
- An external abutment transfers the amplified sound vibrations from the processor to the titanium implant.
- The small titanium implant is surgically placed behind the ear, and is fused with the bones in the skull (through a process called osseointegration). This process allows sound to transfer to the cochlea, which allows the person to hear.
For infants and children under age 5, a Baha system includes a softband headband rather than the surgically implanted titanium bolt. The softband holds the sound processor tight against the head, which allows the sound vibrations to travel to the inner ear.
Who is a candidate for a Baha?
- People with conductive or mixed hearing loss, including those with:
- Chronic ear infections
- Surgically altered ears
- Congenital malformations
- People with single-sided deafness
- Please note, there are two medical devices available for the treatment of single-sided deafness (the Baha system or CROS hearing aids). Neither option restores hearing on the deaf side, but they can improve the perception of sound and increase speech understanding by broadening the perceptible sound field.
Left: Patient without Baha sound processor in place, Right: patient with Baha sound processor in place.
Photos provided courtesy of Cochlear™ Americas, © 2009 Cochlear Americas.
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