This used to be my "superpower" as a kid. I could always tell when the television was on without even looking at it and with seemingly no sound. Sometimes when a TV takes a long time to start and my parents would keep pressing the start button, I would tell them to just wait because the TV had already started and is just loading. Other times when someone would watch the TV on mute (to avoid disturbing sleeping people in house) i could still tell the TV was on because of this sound. I genuinely thought I had a superpower,(reply>), There is nothing unique about me or my life I guess,(reply>), To this day, I can't watch VHS tapes on my parents' old TV, because the high-pitched whine drives me nuts.,(reply>), Same!!,(reply>), My high school had a whole room full of Apple ][ computers. As Tom explained, the monitors made a high pitched noise, so it was easy enough to check at the end of the day whether all the monitors had been turned off. It was only after all the monitors got shut off that I could hear if any of the computers themselves were still running.,(reply>), My version of this is I can hear the very high pitched whine coming from certain chargering plugs. Higher power ones are the worst for it like my Samsung fast charger.<br>It's not a constant thing since e my brain just tunes it out I guess but it's more noticeable when I have a headache or aren't feeling well.