Also commonly called an auditory osseointegrated device (AOD), bone conduction hearing aids serve as an alternative to traditional hearing aids. These devices are often utilized by individuals who have certain types of hearing loss or problems within the outer or middle ears. Bone conduction hearing aids (BAHA) are useful for mixed and conductive hearing losses, as they transfer sound via bone vibration directly to the cochlea while bypassing the middle and outer ear.
How Bone Conduction Hearing Aids Work
As mentioned earlier, these bone conduction devices work in a relatively simple fashion utilizing modern technology to bypass problems within the middle or outer ear. Essentially, these hearing implements pick up sounds via tiny microphones and translate their vibrations into signals passed along through the bone of the skull. These ‘messages’ then travel to the inner ear in the form of sound. Many individuals prefer bone conduction hearing devices over traditional hearing aids. This is because they can often go unnoticed, while hearing aids can be bulky and uncomfortable in the ear canal or make odd telltale noises when in use.
Types of Bone Conduction Hearing Aids
Bone conduction hearing aids have two essential components: an internal implant surgically placed in the bone behind the ear and an external processor. However, for individuals who are not candidates for implant surgery, there is a non-invasive conduction device that attaches to a specially designed headband that is highly versatile and effective.
Concerning implant options, there is one type that fully implants beneath the skin and works with a magnetized system. A magnet is implanted into bone material just beneath the skin behind the ear. Then, an external magnet that is attached to the bone conduction hearing aid connect the two components, sending the signals to amplify sound vibrations.
A second type of osseointegrated system uses a fixture that protrudes from the skin that secures the processor attachment. A small implant is placed behind the ear similarly to the magnetized procedure. However, a small abutment will stick out from the skin, and the bone will grow around it to create a permanent stabilizer for the external processor without the need for a headband.
Companies that you may encounter during researching types and brands of conduction hearing devices include Cochlear Americas, Oticon Medical and Sophono, Inc. Your medical providers will help you determine which type is best for your needs based on the type and severity of hearing loss, age and other medical considerations that may complicate using the device.
Am I a Good Candidate for Bone Conduction Hearing Devices?
Most individuals five years and older suffering from hearing loss due to problems of the outer or middle ear as well as those who suffer from a mixed type of hearing loss are likely good candidates for these devices. In particular, this can become a last resort for those who have found traditional hearing aids to be ineffective or challenging to live with. Surprisingly, infants in good health can be fitted with the headband style aids until such time they opt for an implant procedure post the age of five years. Some common conditions that would make one a viable candidate for bone conduction aids include:
- Ear Canal Stenosis
- Aural Atresia
- Bone Abnormalities of the Middle Ear
- Mixed Hearing Loss Due to Chronic Ear Infections
- Single Sided Deafness
- Cholesteatomas in the Middle Ear
- Excessive Drainage in the Ear Canal
If you are considering having this procedure, you will need to be evaluated carefully with a medical provider and audiologist that has experience with auditory osseointegrated procedures and systems before moving ahead with any type of amplification device.
Testing to Determine Suitability for Bone Conduction Headbands & Implants
An audiologist will perform a series of tests to determine the initial level of hearing remaining. Several frequencies and sound levels will likely be issued through speakers, headphones or a trial conduction headband device. A bone conduction threshold level will be determined for at least one ear, and these measurements are taken through an auditory brainstem response test or a behavioral hearing test. Potential candidates will also need to see an otolaryngologist, which is an ear, nose and throat specialist to get the final go ahead for a bond conduction hearing implant or device.
Additional Benefits of Conduction Hearing Devices
Many individuals find that a bone conduction hearing aid makes a world of difference in their daily lives. These devices allow users to hear things more clearly in many cases, without all of the drawbacks of traditional hearing aids like constant battery changes, static interference, and bulky models that often cause discomfort in the ear canal. Furthermore, frequent ear infections and excessive draining can make hearing aids infeasible to wear.
Another benefit of bone conduction hearing devices is that they are compatible with most telecoil or hearing loop systems. This allows one to use the aid along with other assistive listening devices by simply activating an on-unit switch. Many people taking advantage of conduction hearing implants report better results than with hearing aids, and while they will not fully restore normal hearing, they can help one communicate and manage typical daily situations with greater ease.