I have a HTPC with a ASUS P7H57D-V EVO motherboard and an i5 processor/GPU. I am using HDMI audio out to a Panasonic TV. HTPC is running Ubuntu 12.04 LTS with MythTV 0.25. In most applications I get an intermittent, metallic buzz noise every 10 to 12 seconds. The noise lasts for a second or less each occurrence.
The noise is audible through any application except MythTV. As a result, I'm confident it isn't a physical problem or any particular media file (the same mp3 will sound fine when played with MythTV, but will buzz with Rhythmbox).
I've spent a lot of time playing around with my .asoundrc file (some reading suggested a resampling issue) and a few snd-hda-intel models.
After having spent hours on this issue, I am hoping someone who knows more about alsa and HDMI can tell me if I'm at least on the right path or if I should be looking somewhere else for the resolution. Honestly, I'd be happy if I could just get Hulu Desktop to stop making the noise (in addition to MythTV). For instance, since I launch Hulu Desktop from MythTV, can it somehow inherit MythTV's audio settings?
Thanks for your time!