A patent application submitted by Google shows that Google Glass might be using bone conduction technology
to allow users to hear audio with complete privacy. Unlike earphones, which others can hear at certain volumes, bone conduction brings complete privacy and is more convenient. With the inclusion of at least one "vibration transducer," there is no need for the user to have direct contact with the speaker on the device. Instead, the ear hooks and the nose pad, which do touch the user, will be used to pass any vibration-based audio to the person wearing a Google Glass unit.
Last month, the chatter around the device was that it was designed to send audio directly to the mastoid process. The patent application is for a "Wearable computing device with indirect bone-conduction speaker
." Of course, this doesn't mean that Google Glass will include the bone conduction method to pass along audio, but with the patent application, it means that Google has been working on such a system. And it actually seems that bone conduction technology would be a perfect fit
for Google Glass.