I live in a 3 level center unit townhome and recently (over the past 2 months) I have noticed a "pinging" noise in the wall of the front bedroom. The noise sounds like a heart monitor in a hospital. It is a constant 24/7 and in rhythm beat. It doesn't change if it is raining or sunny. This bedroom is on a wall that is next to my neighbors spare bedroom. I asked her if they had just purchased a grandfather clock or had something in that room that made that type of sound. She has not. They do not hear the sound in their home. It's driving me nuts (luckily it's not bothering the 4 year old occupant of that room) and I want to rip into the wall! BUT I can hear the noise on the ENTIRE 1 side of the room's wall. The sound cannot be heard in the lower level bathroom which is what is below the bedroom.

Any ideas?

Could be a bomb! Duck!

Just joke! It's probably just the Mayan Clock winding down.

Something rhythmic has to be coming from something like a fan or motor or furnace or a pump I would guess.

More details please. Can you describe the sound a little better? Is it pinging, knocking or ticking? I ask this because a grandfathers clock ticks but doesn't ping. Back to you, Tom