New to the forum. Hello to all. A little about me: I work in an aviation hanger. What I'm looking for is some headphones that I can make the case to my safety gurus that they are also hearing protection. The noise level is considerate with either the people around me or myself operating rivet guns on aircraft structures. I need for the headphones to be wireless and for the battery to be rechargeable and to last for preferable near ten hours. I also need something with decent volume so I can hear. Outside noise cancellation and blutooth capabilities would also be nice but not a must. I have so far considered a bose set and the sennheiser mm450 and 550. Both have bad reviews on volume level which is important to me. I plan to use this on either an iPhone 4 or one of the iPod selections since my management has banned cell phone use on the floor. The real reason I'm willing to fork over this kind of money is I plan to use this to listen to textbooks and study material I have downloaded to iTunes. I will listen to music only after the semesters are over. Any advice is appreciated. Thanks in advance.