I dont know if this is a known bug but on my s4 the sound gets cracky and makes popping noises at the end of every pvp match and occasionally during regular gameplay and when in town.

The best way to describe the way it sounds its like a loud noise that sounds like something is being scratched... or like the sound of your ears popping when they have pressure, like swimming or airplanes.

I don't think this is my device because I played my music full blast and nothing happened. It's only when I play pocket legends... :/