“Bone conduction” headphones are among the strangest things you’ll try. But they transmit audio in an amazing way while keeping your ear canal open to other sounds.
It’s a bit trippy. But it works. And it’s about 1,000 times safer than AirPods for outdoor activities like biking, driving, or running.
Sensing an opportunity to solve a major problem, Conduit Sports is one of the first manufacturers of “bone conduction” headphones. The company’s co-founder, David Nghiem, sent a pair of Conduit Motion headphones to our offices, and I immediately demanded an explanation.
How do these over-the-ear headphones transmit audio?
A few days later, Nghiem joined us on the Digital Music News podcast to discuss how “bone-conducting” headphones actually deliver intelligible audio to the brain.
The simple explanation is that bones around your ear canal can pick up vibrations and transmit them to your inner cochlea. The inner cochlea houses tiny hair-like cells called cilia, which then trigger nerve impulses that are interpreted by the brain.
But the actual source of the sound waves isn’t critical – they’re ultimately interpreted by the ciliated cells in much the same way.
“The cilia don’t care where the vibration is coming from,” Nghiem said. “They don’t care if it’s coming from your eardrum, they don’t care if it’s coming from your bone.”
This explains why the way you hear your own voice is different from a recording. “When you hear your voice reflected in a recording, it sounds very different than the way you hear yourself,” Nghiem explained. “When you speak, sounds travel through your body to the internal cochlea, making them sound a certain way that’s different from what someone else hears.”
A similar principle applies to bone conduction headphones. “Imagine having a stereo almost in your head, vibrating through the bones of your body much like your own voice vibrates through your bones when you talk to yourself.”
Sounds fantastic in theory. But in practice it actually works.
However, it should be noted that the overall sound quality is not top-notch. For audio-like podcasts, that makes little difference, although the fidelity for music is significantly worse than a high-end headphone or even AirPod experience.
But Nghiem sees one major upside: her life.
Instead of blocking out noise, the Conduit Motion headphones let in outside noise. This significantly increases safety for cyclists, which is why Conduit is pursuing this market first.
Interestingly, the city of Washington, DC, which is minutes from Conduit’s offices, just passed a law banning traditional headphones while cycling.
The rationale behind this law is clear, and accordingly other jurisdictions such as California, Oregon, Philadelphia and New York City are following suit. All of this could prove to be a boon for companies like Conduit.