Apple has filed a new patent for technology that could be used in the upcoming AirPods 3, a system that delivers audio through bone conduction as opposed to the common air-based method.The new technology allows users to hear audio content without any earpieces, bypassing the eardrums and transmitting sound to the inner ear through bones in the skull. It’s the same technique that near-deaf composer Beethoven used when writing music: he bit down on a rod that he hooked onto the piano to hear its sounds. Bone conduction appears to reduce the risk of damage to the eardrums but the downside is that high frequencies cannot be delivered with the current technology. Apple, however, has drafted a design that also integrates air-based high-frequency transmissions to compensate for the limiting mid and low-frequency capabilities of bone conduction.
Apple may be working on AirPods with better sound and better accessibility for people with hearing impairments. The U.S. Patent and Trademark Office has granted Apple a patent for an “apparatus for delivering audio signal” that uses both your typical air-based sound conduction, plus something known as a “bone conduction transducer. “If this is a blueprint for AirPods that exploit the relationship between bone structure and vibrations in your skull to create sound outside your ear canal, it’s a game changer for people born without external ear canals, or those who find earbuds painful or ineffective.
According to the background information in the patent, bone conduction headphones let you hear audio directly through vibrations in your skull. Air conduction headphones, by contrast, first convert sound signals into air vibrations your ear can detect.These kinds of hearing devices have several advantages. Because they don’t obstruct the air in your ear canal, the headphones make it easier for you to hear external sound while listening to your audio. (That’s especially important for runners.) And since air isn’t required for sound transmission, this kind of technology could enable underwater headphones.
Most importantly, bone conduction headphones are a good alternative for people whose auditory pathways may have been impaired or damaged.Still, there are drawbacks, including high-frequency sounds, which the inventors say is a major challenge. Human hearing generally ranges from 20 to 20,000 Hertz (Hz), per the patent, but bone conduction technology begins to decline at ranges higher than 4,000 Hz.And, in a weird twist, you might actually be able to feel the sensation of sound—as in, directly through the bones in your head, which probably isn’t as nice as feeling the bass vibration in your Beats Solo headphones. The inventors actually describe this as “a tickling sensation to the user, which can range up to annoying.”