> On some LCD monitors this page will cause the screen to emit a tone that varies in pitch with the bar height. Maximize window for best results.
Looks like any noise is the by-product of the electronics within the device, rather than anything playing through the speakers. Coil whine (or something to that effect), I imagine.
I wasn't aware that different screens necessarily produced the same sounds, but I noticed many years ago with CRTs that there was a faint sound that changed depending in a general way on what was displayed.
The noise should be generated by your LCD screen and is usually faint but exant. The larger the area it occupies the louder it is, so it's recommended to maximize it. You might also have an LCD screen that doesn't emit sound, but I don't know the details.