a close of up an earEveryone knows that ears are for hearing, but some new audio technologies are skipping the ears entirely: they are going straight for the bones. New advances in bioengineering have brought sound directly to the inner ears. Technology using bone conduction—the process of delivering sound to the inner ear by vibrating the skull’s bones—makes it possible for the deaf to hear. Bone conduction is used in consumer electronics, the military, and more.

Bone conduction technologies are beginning to replace cochlear implants for restoring hearing to deaf people. Cochlear implants, while successful, are not possible for everyone. A new bone conduction device makes sound available to people who cannot use cochlear implants. Bone-anchored hearing aids (BAHA) bypass the ear canal by relaying sound from a microphone to an implant under the individual’s skin. The implant converts the sound to vibrations, allowing the person to hear.

Bone conduction is not just for deaf people, it is also appearing in military gear and consumer products. Bone conduction technology is popular because, unlike headphones or ear buds, bone conduction devices do not block out ambient noise. Users can hear what is happening around them while listening to music. Navy SEAL teams use bone conduction communication while on missions, but anyone can get bone conduction in their lives through new bone conduction headphones made by companies like Aftershokz. Google Glass also uses bone conduction to communicate sound to the wearer.

Consumer technology using bone conduction is becoming popular partly because it is considered safer than the alternatives. Since people wearing bone conduction headphones are not cut off from their environment, these sorts of devices are safe and legal when driving. The Audiology Foundation of America has given its approval to these headphones, saying that they cause less ear damage than normal ear buds.

The technology of bone conduction is still developing. Some new products have drawn criticism. For example, critics of a train system that uses bone conduction to play messages for riders leaning their head against the windows state that there are privacy issues that must be resolved before the technology is widely deployed.

Researchers are still investigating the many applications of bone conduction. Its ability to stimulate the vagus nerve has proven effective in therapies for developmental disorders like autism. There may yet be many untapped uses for bone conduction in therapy, consumer electronics, and more.

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