First off, you don’t need to be playing it overnight. The Official Sapienmed FAQ (Updated) tells us that 10 minutes of any field is enough.
If you’re concerned, reduce the volume to really low and put your player somewhere that’s outside of his energy field but still within yours. (If that’s not possible, then don’t play your field.)
Only you can answer your own ethical questions. As you’re seeing here, many of us don’t have the same ethical challenges that you’re having.