Headphones Buzz With Fingerprint

[warhammercasey]

I was playing a game with my headphones in, and on a loading screen, I opened my iphone 6s using the fingerprint scanner. When I did that my headphones started buzzing, mostly in the ear closest to my phone. I took my finger off it and tapped it sporadically to make sure that is what caused it and It was. Im just interested on what's going on. My headphones dont have bluetooth and were connected to my computer with a wire (Also close to my phone). They also have microphones on each ear that pick up the sounds from outside and play them from inside at a controlled volume that I set so it sounded the most like I wasent wearing headphones, but it still picked up more sounds then I can normally hear.