Anecdote:

One time about 12 years ago I had a rental car driving to DC to do some work. I had brought along a portable CD player with cassette adapter so that I could listen to music on the trip up. I also had a cell phone with me, a MicroTAC that I kept in a pocket in the dash below the radio. People were calling me throughout my trip. I quickly noticed the ditditdit induced in the cassette adapter cable before the phone would ring.

However, it took me at least a dozen calls before I realized that somehow the portable CD player was pausing on its own each time I got a call. I can only imagine that the voltage induced in the cable got sent back to the CD player over the headphone port it was plugged into and caused it to freak out. It would be really neat to think that somehow some engineer got the bright idea of watching for that signal and automatically pausing the player, but I imagine that it was simply fortuitous.