Do you know of any studies that have been conducted on the effects of these supersonic frequencies on people? I know I've woken up agitated the moment people have turned on a CRT telly, but that's hardly bat territory... I just wonder if there's some harder to quantify effect of these things that perhaps people aren't conscious of?
CRT's emit an audible hiss... particularly when you turn them on or off. Hit the "Degauss" button on one and you'll hear it.