What could cause a vibrating/humming noise in my wall?

Question

For the last 24 hours or so I have noticed a humming type noise coming from one of the walls of my townhouse, it seems to occur every 15 minutes or so and lasts for a few seconds. My neighbour hears it as well, but he says not as often as I do. I was hoping someone has seen this before as I am not sure who to call out to have a look at it.

Answer 1

Could it be a toy a lady uses that has been dropped into the cavity!!

Seriously :-

1) Bathroom extractor fans, door bells and halogen ceiling lights can have transformers in strange places.

2) A stopcock can cause pipes to vibrate

3) Air gaps behind dot and dabbed plasterboards can let the wind whistle through

All you could do is try to listen where it gets louder to find the source of the problem.

Answer 2

Momentarily shut off the power to your indoor unit(a/c) when you hear the noise and see if it stops.The control transformer in your indoor unit sometimes will make an extra loud hum that can be heard through the walls.

Answer 3

Boiler.

Answer 4

Probably the electric lines.

Answer 5

Is there a doorbell tranformer in the vicinity?   It could even be in the attic, or if that wall has a garage or other access, it could be in there.

Occasionally, transformers will hum, though usually when they're under load.   Sometimes they'll buzz when a lamination in the transformer core is loose, and that can sometimes be intermittent.

If that's what it is, replacement is about the only option.

Answer 6

are you noticing little bits of cement on the floor where the noise is coming from?if you do have bits of conrete you could have mortar bees which will need a builder to come out and get rid of them.i have seen this once and the damage they did was astronomical.