How bone conduction headphones work

Sound is not only transmitted through the eardrum, you can also use the bones of the jaw and jawbone

The new frontier for listening to music is bone conduction. We're used to using headphones (in-ear, on-ear or over-ear) to relax on the couch and hear our favorite singers. And we also use them at work to listen to music without disturbing colleagues or for Skype calls.

The future of headphones, however, will be completely different. And new models of earphones will come into play. In this change, bone conduction will be the main feature. The auditory system is not only formed by the eardrum, the bones of the jaw and jawbone also propagate sound. In fact, man hears his own voice thanks to the bones in his face. No one has ever used the facial bones' ability to conduct sound to listen to music or movies from a computer or smartphone. For the past few years, however, things have changed and some companies are making bone-conduction headphones. Here's how they work.

What bone conduction headphones are and how they work

Bone conduction headphones are earbuds that don't use the eardrum to propagate sound, but the bones of the jaw and jawbone. Back in the 19th century, Beethoven had already realized the ability of facial bones to conduct sound: suffering from hypoacusis (a disease that leads to complete deafness), he tied a rod to the piano strings and held it between his teeth. Thanks to this stratagem he was able to hear the sound produced by the musical instrument. Even whales are able to pick up ultrasound through their jaw bones. So it's not just a human characteristic.

Bone conduction headphones work in a completely different way than the normal earphones we use during our everyday life. Instead of being inserted into the ear canal or resting on top of the earcup, bone conduction headphones rest where the jaw meets the ear. Sound bypasses the eardrum and travels directly into the middle ear canal and into the cochlea, the innermost part of the ear.

Why choose bone conduction headphones

While not yet widely used, bone conduction headphones have several advantages over regular headphones. For example, they allow people to hear what's going on around them. When you're exercising and listening to music with a pair of in-ear headphones (the ones you put inside the ear cup), you're unlikely to be able to hear sounds coming from outside. And that can be a problem, especially for your personal safety.

Bone-conduction headphones, by using the bones of the jaw and jawbone, also secure the eardrum, preventing injury from too much sound.