I have a partial tear in my quadriceps above the knee and i went to have an MRI done, the tech/nurse said it would take 20 min and asked if i wanted to listen to some music and i said yes and he put some headphones on. the sound was absolutely the worst all garbled and the only thing that was kind of clear were drums. it was so bad i commented to the tech when i was done. he said that unfortunately metal or wires cant be anywhere in the room. these things give wireless headphones a whole new meaning. i looked at them and they were connected with a clear vinyl tube. not sure how they worked, sound is pump through in the air ??? just thought i would share and see if anyone knows how these work.