XPS 17 Sound Issues Through Laptop and TV

I have an XPS 17 (L702X) and am getting a periodic distorted buzzing noise when playing music or watching video with sound.  It doesn't matter whether I am dealing only with the laptop speakers or if I am running video to my TV through the HDMI, (the buzzing comes through the television speaker too).  

Any suggestions where to start trying to figure out the source of the problem?