I think the dogs can hear our induction stove with ultrasonic whine, but somehow my cat will sleep blissfully in a room with a VGA CRT whining from 30-80 kHz (perhaps quieter than the stove), and used to sit in front of a CRT TV whining at 15.7 kHz so loudly I couldn't stand it without headphones.
When I was a kid I noticed that the adults in my life couldn't hear that CRT sound. My son bought a CRT TV with a built in VCR to use with a Nintendo 64 to get out the last frame of latency. I noticed the other day that I can still hear that sound, but I've always had sensitive hearing and I've always kept amplified sound at a low level and worn ear protection while using machinery, going to motorsports events, etc.
(In the past I have volunteered as a sound man for live music events but I have never been at a venue which I thought wasn't too loud in terms of absolute sound pressure or in terms of there being audible distortion in the amplifiers & speakers, so I haven't made a habit of it. My son won tickets to a 38 Special + Foghat show that we went to last week, I didn't mind the loudness much but it was clear to me they were pushing the sound system just a little too hard.)
I remember in school, we'd often hear the TV whine and know we were watching a tape in class that day without needing to look up at the TV (mounted high in the corner by the ceiling.) The teachers used to wonder how we knew and didn't believe us when we said we could hear powered on TVs.
