The mind control part of an episode...Help plz.

There were a portion of an episode and I accidently deleted the show off the DVR too quickly w/out thinking that contains the name of an equipment. It was shown a circular device attach to a guy's forehead w/out using his ears and its plugged into a portable CD music player. He was able to hear it in his mind as if it was traveling thru his ears. What device are those and where to obtain?