All CRT TVs did it right until their death, but in my lifetime I've never heard it from a Computer Monitor. I've always hated this sound,(reply>), @Okaro its due to the 15Khz horizontal scanning frequency,(reply>), Monitors had higher frequencies, for example VGA was 400 lines at 70 Hz on text mode that makes 28 kHz. Because of vertical retrace it actually was higher, about 30 kHz. Better monitors were even higher.<br><br>Similarly 100 Hz TVs were immune to it.