There is another problem you may need to be aware of with wireless head 
phones.  I have a set of wireless speakers so that I can listen to an 
Internet stream while in another room.  Once, my neighbor from across the 
street said that she was jogging with her wireless head phones on listening 
to her stereo when she heard things like, "Jaws for Windows is Ready," and 
other things.  So sometimes, head phones are programmed for the same 
frequency as wireless speakers.  So if you are ever reading private email 
and you have wireless speakers, remember to turn the transmitter off.  73.
Harvey