Only SD CRTs make an audible shrieking sound. LCD computer monitors were replacing VGA or better CRTs with a horizontal refresh rate of >30kHZ. Maybe they could annoy your dog but no human could hear it.

I still use a 130kHz CRT monitor sometimes. There's no 15kHz whine, but there's audible harmonics. It depends what you're looking at at and how hard you're pushing it.