Strange PWR noise - what could this be?

[living sounds]

This sound comes over the power lines, it can be heard on the monitors, even on some gear. It can occour at any time during day or night, unpredictably as far as I know. This time I was lucky to catch it - while fixing a hum problem (that's why the sample has a lot of hum in it).

Do I need some kind of filter or power conditioner for my studio?

Noise

 

[MagnetoSound]

Power tools? Doorbell?

Could be signalling. Do you live near a railway line?

Do I need some kind of filter or power conditioner for my studio?

... guess you do!

 

[emrr]

Power co. test signals.  Once you notice them you will hear them all the time. Power co. can install filter, tech will probably deny hearing it. 

 

[living sounds]

Thanks guys! So it's definitely a test signal from the power co? I'm not sure I can force them to install a filter, what can I do myself to get rid of it? Any suggestions for a filter? Thanks!