Help With Noise Distortion Through Line In

LightsOut23

Honorable
Dec 21, 2012
31
0
10,540
I'm attempting to use line-in via the motherboard (Asus P8Z68-V) to play sound files from my phone. When using my iPhone, at high volumes I get a bit of white noise (fuzzy distortion) when no music is playing which is expected. That isn't a problem, I just used it as a control to make sure it wasn't the input or cable.

My problem is when I plug in the LG G2, in conjunction with the white noise I get a type of noise that sounds similar to a radio-like frequency distortion. When I play something, this distortion is gone both while the audio files is playing as well as a couple of seconds after the file is done playing. It then it persists again until something else is played. What could be causing this and does anyone know of a fix?