One of the biggest drawbacks of headphones is that they block oxygen supply to the ears. Hence when you use them more than a few hours a day you start getting ear related problems. So my idea is a head phone that won't give you any problems, even if you use them for 8 hours+ or more ( you know people in the service industry call centers etc , basically those people who are not audiophiles.) These head phone will have two modes, simple (no amplification) and powered mode (sound...