This only happens with TVs or very low quality monitors. The flyback transformer vibrates at a frequency of ~15.7k Hz which is audible to the human ear. However, most PC CRT monitors have a flyback transformer that vibrates at ~32k Hz, which is beyond the human hearing range. So if you are hearing the high frequency noise some CRTs make, it is most likely not coming from a PC monitor.
Its a sound thats a part of the experience, and your brain tunes it out pretty quickly after repeated exposure to it. If the TV is playing sound such as game audio or music it becomes almost undetectable. Unless there is a problem with the flyback transformer circuit, which causes the volume to be higher than its supposed to be.
There is not one crt I ever encountered that I couldn’t hear. So I’m having trouble believing you information.
I could time it out most of the time, but it was always there.
https://en.m.wikipedia.org/wiki/Flyback_transformer
Under “Operation and Usage”:
In television sets, this high frequency is about 15 kilohertz (15.625 kHz for PAL, 15.734 kHz for NTSC), and vibrations from the transformer core caused by magnetostriction can often be heard as a high-pitched whine. In CRT-based computer displays, the frequency can vary over a wide range, from about 30 kHz to 150 kHz.
If you are hearing the sound, its either a TV or a very low quality monitor. Human hearing in perfect lab conditions can only go up to about 28kHz, and anything higher is not able to be heard by the human ear.
Either that or you’re a mutant with super ears and the US military will definitely be looking for you to experiment on.
On a side note, I can also hear when a capacitor is going bad on an lcd when other people around me cant hear it.
It could be something else in the crts I’m hearing, but I can definitely tell one is on without seeing it. It’s been like this since the 70s for me.
I can also smell and taste things other people can’t, so something is a little different in my brain somehow.
My partner and daughter tell me I have super powers lol. Guess who gets to smell meat for rot? Not them! Bleh.
I’ll defend this guy: there can easily be a harmonic at half the flyback frequency that is audible. It’s lower amplitude so less loud, but I could believe someone being able to hear that.