Just bought a 6s yesterday. I put iOS 9.1 beta on it and am not hearing any electronic noise. I am using Audio Technica ATH-CK10's (107dB/mW) and I have the IM02 at home. I tried to replicate what OP was doing in the video and could not reproduce it. Maybe they fixed this in 9.1?
9/29/15 at 7:32am