Copyright© Françoise Herrmann
This bone conduction audio technology is standard gear in the Army. Instead of inserting an ear bud into the ear canal or headphones over the ears, the hearing device in housed in helmets or protective headgear, in glasses, or placed directly on the cheekbone or other part of the user’s head for transmission of sound to the user’s auditory system via the user's bone or other tissues. This leaves the ear canal open to capturing ambient sounds such as sirens, the sounds of a vehicle approaching or communication from other people. It is much safer, and just as effective in terms of sound transmission.
The technology consists of piezolelectric transducers, integrated or housed, coupled to an amplifying circuit and audio source. The amplifier circuit can further be equipped with receiver technology for wireless reception of sound signals. It may have a battery or be solar powered. It works simply bypassing the eardrum, sending sound as vibration directly to the cochlear bone via bone and other tissue. Thus, instead of sound hitting the ear drum through the ear canal where the vibrations are transmitted to the cochlear bone, which in turn transforms the vibrations into signals transmitted to the brain for decoding via nerve cells, bone conduction sends signals directly to the cochlear bone which then functions as if the vibrations had come from the ear drum.
Compared to regular earbuds or headphones, bone conduction audio simply reduces risks, whether the invention is embodied for Army personnel or for runners and bikers on the road. One marketed product is called Aftershokz®!
Abstract [US2009060231] A stereo headphone includes a first audio element and a second audio element to be positioned against sides of a user's head in which each of the first and second audio elements is configured to transmit audio signals through bone to the auditory system of the user.
Bone conduction headphones [US2009060231]