This may have nothing to do with Ubuntu, it may be an issue with the monitor, but if anyone could identify that you guys could. Also I just read in the "please read" that the forums are not for general support questions which is, I think, all I've ever used them for. So my sincere apologies if I am miss using this incredibly valuable resource, and if I should be searching elsewhere please give me a lead.

So I am running Ubuntu, and only Ubuntu, 12.04 on a Toshiba Satellite. I often connect the system via HDMI to my Philips LCD monitor for movie watching. This works almost perfectly. The system automatically detects the monitor and video and audio both come through. The problem is that every ten to thirty seconds there is a prominent squelchy hiss that lasts about half a second. The noise only happens when there is audio playing (youtube, VLC, Netflix, etc..) if there is nothing to be heard: no squelch. Also, it gets louder and quieter with the adjustment of volume on any of the players or hardware involved.

Any ideas?