Actually I can tell fairly certainly from the direction the noise comes that it's not the monitor - the noise comes from speakers (which are separate and apart from the monitor) and it starts when I press the scroll wheel on the mouse - I need to see if a wired USB mouse causes that or not.
I think the other commenter thinks your monitor is causing the interference which is causing your speakers to create sound. The trick would be to turn off the monitor and see if it still results in sound when scrolling, or just scroll to the bottom of the page and keep scrolling without having the monitor change in any way.
