Mains hum

I have tinnitus and when it's loud enough to hear over that, it just makes it worse.

Rick

I must confess that I do like a good old bit of power hum listening.

It is the initial condition assessment of high voltage electrical apparatus, particularly power distribution and generator step-up transformers.

At home I know it is the capacitor for the well pump startup. So I am getting anxious about when it is going to fail.

anywhere else I am just curious what piece of equipment it is that makes the distinctive sound.

Humming switch mode power supplies are much scarier to me.

- W.

It's good and bad. I just heard a hum yesterday. It told me that power was getting to an AC powered motor and that the passive components ahead of it may need replacement. Turns out the motor brake was causing the issue (after the burnt out wires from the main were replaced). The humming let me know that the troubleshooting was paying off because at first plug in there was no hum through the coils.

Being able to hear electricity puts me on edge.  I'm okay with contactor hum but I shouldn't hear sound from a breaker panel or even a fluorescent light ballast.  I guess I expect it in a substation, but the hum in a foundry makes me anxious.  Tens of thousands of amps is almost inconceivable.  I work with mains power regularly so my position is "If I can hear it, it needs to be fixed."

Loud AC Hum always catches my attention as it either means that there is high enough voltage and current to cause the noise or there is something wrong like a bad ground in audio cords or poorly designed or mounted transformer. The hum is a challenge to find out what is going on, hopefully before there are flying caps as described by Gene.

John

I don't like it but I don't hang around high power AC if I can help it so I don't think about it much.

Hum as it pertains to analog signal noise is annoying to deal with, but not dangerous.

I think about the possible impacts over the long term. I'm assuming if you can hear the hum your close to the source.

I worked in an RF environment for 17 years. I made every attempt to limit my exposure to RF in and outside the environment. I just short of wearing a tin foil hat.

Story. We had a person stand in front of the antenna for a ground based aviation radar. The fail safe were in over ride to do some work. The individual had major health problems for a large part of his life.

Working with AV, it is a nuisance...

I've never had any of such experiences, nor do I often get close to large AC devices, but the hum still makes me anxious. The noise in some way reminds you that you are not safe and you could die at any moment if you are not careful or things go wrong.