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RightHandOfIkaros@lemmy.world ⁨2⁩ ⁨weeks⁩ ago

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.

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systemglitch@lemmy.world ⁨2⁩ ⁨weeks⁩ ago
There is not one crt I ever encountered that I couldn’t hear. So I’m having trouble believing you information.

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- RightHandOfIkaros@lemmy.world ⁨2⁩ ⁨weeks⁩ ago
  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.
  
  Either that or you’re a mutant with super ears and the US military will definitely be looking for you to experiment on.
  
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  - errer@lemmy.world ⁨2⁩ ⁨weeks⁩ ago
    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.
    
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    RightHandOfIkaros@lemmy.world ⁨2⁩ ⁨weeks⁩ ago
    Yes, as I previously stated, if there is a problem with the flyback transformer circuit, it is possible that the frequency or volume of the noise it generates can become increased or different.
    
    Though again, PC monitors never made an audible noise unless they were low quality and used the cheaper 15.7kHz transformer in their construction.
    
    Other noises associated with CRTs are the degaussing noise, which only happens once usually after turning on the CRT or after pressing the degauss button, or the sound of old ODE hard disks spinning, which also make a high frequency noise.
    
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  - systemglitch@lemmy.world ⁨2⁩ ⁨weeks⁩ ago
    Please don’t tell them about me.
    
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    RightHandOfIkaros@lemmy.world ⁨2⁩ ⁨weeks⁩ ago
    Your secret is safe with me.
    
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  - systemglitch@lemmy.world ⁨2⁩ ⁨weeks⁩ ago
    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.
    
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    Cypher@lemmy.world ⁨2⁩ ⁨weeks⁩ ago
    You’re not alone, I can hear CRTs, bad capacitors and an array of other electrical appliances.
    
    I can still hear the high frequencies that only teenagers and your kids are meant to be able to hear.
    
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- deltapi@lemmy.world ⁨5⁩ ⁨days⁩ ago
  I could hear them too, when I was younger. I lost that frequency range of my hearing in my mid-to-late 20’s, which I’ve read is normal.
  
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julianh@lemm.ee ⁨2⁩ ⁨weeks⁩ ago
Oh neat, thanks for the explanation! That makes sense as most of my crt exposure for the past 10 years has been classroom TVs and museum exhibits.

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