why does my monitor pop?

[OmegaXero]

Perhaps this is a stupid question but I was wondering if anyone out there could tell me why my monitor makes a cracking or popping sounds when I switch to a different resolution or refresh rate? I run a Viewsonic E771 17inch monitor. It makes a popping sound whenever I change from 800x600 to 1024x768 or whenever I change from a lower refresh rate (75hz) to a higher refresh rate (85hz or more). I know that almost all monitors make this sound but what causes it? Is it bad for the monitor to constantly pop into different modes? For instance, I might play Q3 at 800x600 and then exit to my desktop which is running at 1024x768 at 85hz. Is this bad for my monitor?

 

[OmegaXero]

^bump

 

[Wik]

ALl you are hearing is the sound of a relay.