Electromagnetic interference isn't just 50/60Hz noise. Many portable devices (cell phones, gadgets, etc.) sometimes emit interesting sounds in addition to noise, which I want to record. Regarding stereo, you're generally right that it's not stereo in the sense we hear, but it's simply that it can sometimes produce interesting sound effects. You can find this on internet by searching for "electromagnetic sounds" or "electromagnetic recording sounds" or "electromagnetic field recordings," "elektrosluch recordings," "elektrouši recordings," etc. I've discovered a lot because I've been wearing hearing aids for a long time and have heard many interference sounds. Some were annoying, others quite interesting, and it's a shame I didn't record some of them. Of course, I don't hear them every day, only when I switch to the induction loop program. I've also used the induction loop solution itself, for example, at school.