artwritesyou is a long time friend of my daughter's. When he posted about this issue on Facebook, I had some thoughts about what the problem could be but wasn't sure how to give him advice about troubleshooting and fixing it, beyond the obvious of rebooting, trying another browser, closing all unnecessary programs, and so forth.
Not sure, but it could be a sound card driver. Try updating yours to see if that helps. (It's rare, but happens.)
That was one of the possibilities that I thought of. I also thought it could be a clash between ATI graphics drivers (the sound portion) and those of his sound card. I didn't actually ask him if he has an ATI card though. I have a Dell with an ATI card and updating the drivers cause some issues with sound back when it was fairly new. Ended up having to call Dell's support line to get help fixing it (can't remember what they had me do, though).
I also thought it was possibly a hardware issue...maybe early sign of a hard drive problem? (I remember about a month before my daughter's laptop hard drive died, she started having audio problems that caused it to sound distorted) I didn't want to tell him anything that would make him have an unnecessary panic attack, so I didn't mention this to him on Facebook. If this is a real possibility, you guys could probably give him better advice than me about how to find out and what to do if it is the problem (safely and quickly backing up his data, etc.)
I also thought it was possible that Flash was causing an issue with high CPU/RAM usage, which can also cause the audio in videos to sound distorted.
Also the possibility of a codec issue, maybe?
I sent him here to consult with you guys, the biggest collection of PC smarts and experience that I know, knowing you'd probably know more than I do on how to figure out what is wrong and fix this.