Bone conduction hearing is certainly not new. Earphones for army tank intercoms and radios had them in WW2. And I know that during an audiological exam a few years ago, when they put on the bone conduction earphones I could hear perfectly. I also find that there do not seem to be any inexpensive bone conduction earphones on the market. There is one for about $110, and that was all that I could find. And the $6000 each for top end earphones? That is what the market will bear, since some who have lost hearing are really desperate and will pay whatever the price is for anything claimed to work. To bad about the price gouging, isn't it?