Bone Conduction Hearing Aids

Hearing aids are acoustic devices that are electronically tuned. The apparatus can either be carried by the person in a pocket or fitted behind the wearer's ear. The basic aim of the apparatus is to gather and amplify sound energy.

Today, to offer people with this particular handicap a hands-free experience, bone anchored and cochlear implants are commercially accessible. 'Bone conduction' refers to the conduction of amplified sound gathered by the special device, into the inner ear via cranial bones.

The technology makes it possible to amplify lower frequencies, thus empowering the wearer by the experience of modulated sound. They offer the hearing impaired the versatility of sound conduction that is as effective as listening directly, via a normally functioning ear. The implant is small and comprises a headset and electromechanical transducer.

Bone conduction hearing aids, are ergonomically positioned on the cranial bones. The device is programmed to convert electric signals into the desired range of mechanical vibrations. The sound is directed into the inner-ear, via the cranial bones. 

They also accommodate microphones to record uttered sounds via bone conduction, if desired. The aids are sold as:

• Ears-free headsets.
• Assisting listening devices.
• Underwater or high-noise environment communication products.

These products are rated better than the traditional hearing aid devices. They are not only more durable and safe to use, but also guarantee sound clarity even in a very noisy environment. They offer the perception of stereo-like sound. The versatility of these devices lies in the fact that they can be used by individuals with normal or impaired hearing.

Normal people are known to sport the products when engaged in occupations that demand complete covering of the ears, thus resulting in hearing loss for quite a few hours of the day. This is normally observed in the case of marine biologists whose gear does not permit normal hearing, as well as professional scuba-divers and avid swimmers.

A bone-anchored device works along the ability of the cranial bones to conduct or direct gathered sound. These implants are surgically fitted abutments. The sound conduction bypasses the external auditory canal and extends directly into the inner-ear region. The operation involves the embedding of a titanium post into the skull.

It comprises a sound processor to transmit sound vibrations that stimulate nerve fibers within the inner ear. This process assists the sense of hearing. Through the process of osseointegration, the external titanium fixture merges with surrounding cranial tissue.

The process takes around five months, and hence the bone conduction device can only be used five months after implantation.

There are a number of aids that are fitted with a snap-lock coupling. The coupling allows the device to be clipped onto the abutment. The sound processor runs on the power of batteries for a span of a fortnight, and can be subsequently recharged. The detachable design in these customized aids facilitates the removal of the snap-lock coupling, when not in use, to prevent damage to the tissue and the implant.

Bone-anchored devices or implants are designed to address the needs of people suffering chronic inflammation of the ear canal, as well as people who have malformed ear canals and related ear problems.

They are also part of treatment options for single-sided deafness and bilateral conductive loss, that results from the onslaught of otosclerosis or Down's Syndrome and other similar health maladies.