How does the Cochlear Baha System work?
A Cochlear Baha System uses bone conduction to bypass the outer and middle ear, and directly stimulates the inner ear organ, known as the cochlea. It is based on the principle that sound actually travels much better through liquid and solid materials than it does through the air. Think about how we listen to the railroad tracks to determine whether a train is coming, or about a dolphin’s ability to “see” with sound, and you can appreciate this fact. When ears have conductive hearing loss that impairs their ability to detect the subtle sounds as they travel through the air, using a microphone and transmitting those sounds to the cochlea through the bone or skull of the patient is a very efficient way to improve hearing.
There are three parts to the Cochlear Baha System: the sound processor, the abutment and the titanium implant. First, the titanium implant is surgically placed in the skull behind the ear, where it eventually fuses with living bone. This is a simple operation that does not include significant risk of injury or complication for most patients. A small piece of the implant is designed to protrude through the skin. This is where the abutment permanently snaps into place. The sound processor is then connected to the abutment. This processor is removable. All three elements, when connected, work together to allow the patient to hear normally.
The sound processor picks up sound vibrations from the environment. Sound then travels from the sound processor, through the abutment and the titanium implant, and into the bone. The sound is conducted through the bone to the cochlea in the inner ear, which converts the sound vibrations into electrical impulses that travel to the brain for processing. This allows the patient to hear the sound while bypassing the ear drum, middle ear space and ear canal. In an extreme case, a child born without an external ear, ear canal or ear drum, but with a normal inner ear cochlea and nerve (as happens sometimes), could hear nearly normally with a Cochlear Baha System because the sound waves would travel through the bone of the skull directly to the cochlea.
Who Can Benefit From A Cochlear Baha System?
This type of amplification device is ideal for patients who have conductive or mixed hearing loss. It is also used in individuals with single-sided deafness.
Examples of conditions that are classified as conductive or mixed hearing loss are:
- Perforated or absent ear drums
- Congenital malformations such as atresia
- Single-sided deafness (Due to trauma, viral infection, measles, chicken pox or Meniere’s Disease)
Other factors to consider include severity of hearing loss, speech discrimination scores and anatomy of the auditory system as seen on imaging. Patients under five years old are not eligible for the implantable system, but can wear the sound processor wrapped in a specially designed headband until they are old enough for the implant.
This technology was developed more than 35 years ago and has proven effective in helping thousands of patients who otherwise would struggle to have serviceable hearing with traditional hearing aids. Patients who wonder if a bone conduction system might be the right hearing solution for them should answer these questions:
- Can you only hear from one side?
- Do you have trouble getting sufficient loudness when using hearing aids?
- Do you battle feedback or distorted sound quality when using hearing aids?
- Do you suffer from sore or irritated ears due to your hearing aids?
- Do you have drainage from your ears?
- Do you have malformed ears or ear canals?
Patients who answer “yes” to any of these questions might be good candidates for a Cochlear Baha System and should be evaluated by a board-certified audiologist and board-certified otolaryngologist to learn more about their suitability. For more information on the Cochlear Baha System, visit the Cochlear website.