I know this is totally off topic but may help some of you that were as
surprised and annoyed as I was this morning when I opened my Firefox Web
Browser and found that there was a strange siren like sound running that I
couldn't turn off.  It turns out it's from Google, they have a Pacman thing
running on their browser page for the anniversary of Pacman.  In Firefos you
can get rid of it by loading an add on called Flashblock.
Sorry for the wasted bandwidth but I'm sure others are encountering this.