Attention all 'Sparkies'... What is that annoying hum???

Question

When I am in bed and everything is quiet i keep hearing this annoying hum. It sounds electrical, like theres a fluro light on or something. ( i don't keep any lights on).

My bedroom window faces the street and there is a street light out there and power lines. I can usually hear the hum when I am sitting in my car if it parked on this street even when the street light is not on.

Does anyone have an idea what this might be????

Answer 1

As well as the electrical explanation, it's possible the hum is in your head (tinnitus). If it only happens when sound levels are very low, this is not anything to worry about.

Answer 2

Any device badly tuned will produce a hum, even an electric outlet.

Apply the scientific method:

Inside: at night,  when the ambient noise level is lower,  close your windows, and check all electric devices:

outlets,

Ipod and converter,

clock(s)

radio

television

converter(s) like for your cell phone

refrigerator (the usual suspect)

alarm

and so on.

Outside:  It might be the light or more precisely a transformer for the light. but it must be a fast hum.