Looks like someone has previously marked this as elevated without actually leaving any sort of response.

This is a result of your sound file having 48KHz sample rate and SDL_Mixer 2.6.2 having some sort of problem playing those correctly.
Today's update on Steam and the standalone 5.65 release will use a newer version of SDL_Mixer which looks to no longer suffer from this issue, but if you still encounter this weird static sound please post here.