Bone conduction: innovation, technology and hearing loss


Bone conduction has rapidly become an important facet of hearing loss treatment and is making its way into many other areas, including consumer electronics. The ears are not the only portal for sound. Bone conduction can be used to transfer sound to the inner ear through the bones of the skull or other parts of the body. This is one reason why a person’s voice sounds different to them when it is recorded and played back.

Bone-anchored hearing aids (Baha) have been used for some time. They work by conducting sound from a microphone to a magnet or implant in the patient’s skin. Sound is then converted into vibrations in the skull and eventually arrives at the inner ear to be processed as hearing by the brain. This was an important step in restoring hearing in patients who have closed or damaged ears or no functional pathway from outer to inner ear, such as those with microtia or atresia.

The innovation is also starting to make its way into consumer electronics. Bone conduction headphones have been developed that ensure ambient sound is not blocked out, an advantage for sportspeople and drivers. It is also reported that Google Glass (a wearable computer with an optical head-mounted display) will make use of bone conduction to generate sound, instead of relying on a standard earphone-speaker setup. In addition, the technology is expected to move into the area of underwater and deep-sea communication systems, as shown by a number of emerging patents.

The technology has come a long way, as Dr. Sunil Puria, ear biomechanics expert at Stanford University explains, “There has been tremendous progress, from miniaturization, to wearable and wireless, so that we have reached the holy grail of not requiring earphones.”