Why do some Websites make my monitor hum?

Factual Questions
1

Displaying some Websites will cause my Sony Trinitron monitor to emit a mid- to high-pitched hum when I visit them.

Here’s a recent example, which I went to earlier today because it was linked to in another SDMB thread.

It’s not that common, but maybe about 5% of the Websites I visit cause my monitor to hum.

I’ve noticed that it most often happens when a page has a colored background, but this is not always the case.

Does anyone else experience this, and is there an explanation for it?

It is some funky interaction or interference pattern that arises from the electron beams and the phosphorous coating inside CRTs?

Incidentally, the Website I link to above hummed while using IE, but not Netscape Navigator (it actually didn’t display properly in Navigator …). The humming in this example also only occurred in the middle of the Webpage, where the white text filled the screen. When viewing the top and bottom of the page, where there were graphics and some solid white spaces, the humming disappeared.

And to head off all the smart-aleck replies, the actual **content ** of the sites has no influence on whether there is humming or not. My Trinitron is **NOT ** expressing disapproval of some of the sites I visit! :smiley:

2
      • If it bothers you, one thing you can to is go into the display properties, in the “advanced” part and try forcing different refresh rates. Exactly how you do this varies from videocard to videocard, some just let you specify a forced rate directly, where others have a “forced minimum” and “forced maximum” that you have to set to the same value. …One of my two monitors began occasionally emitting a high-pitched whine, horribly annoying and only 8 month old ViewSonics. Forcing a slower refresh rate than what it was defaulting to (70 vs 75 Hz) stopped the whining completely.
        ~
3

Most likely it has nothing to do with the “site” as such, but with the white brightness level the site requires the CRT to display, stressing a component. It’s generally an indicatior that he Monitor’s Power supply or some other hardware component is on it’s way to failure. Turn your monitor brightness level down substanatially and see if this noise repeats.

4

No, it doesn’t bother me per se. I posed my question more out of curiosity than anything else.

I’ll try the suggestions offered, crossing my fingers that my monitor is not on its last legs…