Low-frequency Hum in my house.

[CBM]

This is a little off topic for an audio forum but I'm hoping someone with a microphone can measure the noise in their house and tell me if this chart is normal.

We live in a 89 year old house and for the last few months we have heard a low-frequency rumble sound all the time. Even with everything in the house turned off. It's the same everywhere in the house but we don't hear it outside or under the floor (pier and beam) or in the attic. It's constant and unchanging so I thought I would measure it with my microphone and REW. There seems to be a higher level of noise below 100 Hz on REW.

. I would like to know if this unusual or is it common in a house? It's driving us crazy and causing loss of sleep. The trace is with 1/6 smoothing.

 

[Soniclife]

Are you in a 50hz country?

 

[Soniclife]

What does it look like without smoothing?

 

[CBM]

Are you in a 50hz country?

No. 60 hz.

 

[CBM]

What does it look like without smoothing?

Of course, it keeps changing.

 

[Inner Space]

Even with everything in the house turned off. It's the same everywhere in the house but we don't hear it outside or under the floor (pier and beam) or in the attic. It's constant and unchanging.

Intriguing. Is everything turned off? Main breakers? Could be a pump with bearings going bad ... do you have well water or city water? First step is to turn everything off - electric at the main breaker, gas, water, anything else. Then you might figure it out by elimination.

 

[CBM]

Intriguing. Is everything turned off? Main breakers? Could be a pump with bearings going bad ... do you have well water or city water? First step is to turn everything off - electric at the main breaker, gas, water, anything else. Then you might figure it out by elimination.

We are going to turn off the breaker. That's a good suggestion. I was hoping that someone could tell me if those measurements are reasonable. Thanks.

 

[CBM]

I don't think my phone mic will pick it up. It's so low that you almost feel it rather than hear it.

 

[adc]

I'll be interested in what you find. I just wanted to mention that, as we here know, low frequencies can travel long distances and concentrate or resonate in weirdly local ways. I would not be at all surprised if you find that the source is not on your property, but that it's merely resonating in response to distant industrial machinery of some sort.

 

[Speedskater]

I sometimes have a similar problem, even with a neighborhood power outage. It may last for hours, days or weeks. Some years ago, I had a different louder constant noise, then there was a city power failure, when power returned the noise was gone. I suspect a distant pump or compressor, maybe in the sewerage system.

 

[rdenney]

Does your house have a radon removal system? A lot of old houses have been retrofit with these. These use a fan that applies a partial vacuum under the basement floor. After some years, the fan bearings will start to fail and the fan will need to be replaced. Mine made a rumble with that occurred.

Did someone leave on a bathroom vent fan in a bathroom you don't normally use? Been there, done that.

Less likely, given your descriptions: Do you have a transformer in your yard? Ours is huge (we live in a rural area) and emits audible 60-cycle hum I can hear from 50 feet away. In a neighborhood, that transformer may be on a service pole.

Chest freezer in the basement or garage that you don't inspect very often? But these are intermittent, when the compressor is running.

Rick "who spent a week tracking down the noise radon fan" Denney

 

[Soniclife]

We are going to turn off the breaker. That's a good suggestion. I was hoping that someone could tell me if those measurements are reasonable. Thanks.

You have 3 frequencies that stand above the noise floor, they seem to be at fixed frequencies and volume, so it looks like you are not imagining it and there is a real noise. If you move around the house can you tell or measure it getting louder or quieter? What happens if you measure where you say it's not audible?
A rising low frequency noise floor is normal.

 

[CBM]

You have 3 frequencies that stand above the noise floor, they seem to be at fixed frequencies and volume, so it looks like you are not imagining it and there is a real noise. If you move around the house can you tell or measure it getting louder or quieter? What happens if you measure where you say it's not audible?
A rising low frequency noise floor is normal.

It's really strange. It's all over the house but it seem worse near the walls. I hear it in the bedroom at night, but when I put my ear to the window there's nothing coming in from outside. When I put my head on a pillow, I hear it in my downward ear more than the one exposed to air so it must be vibrations in the structure. Tonight I'm going to turn off the electrical breaker and see if it goes away.

 

[CBM]

I have nominated you for video. Do your best and play the video back to check to see if it is, satisfactory enough someone here will be listening.

I will try to get some audio tonight when the ambient noise is low.

 

[McFly]

Yeah, I'd pull the mains fuse at the street if possible, switching the house mains breaker doesn't rule out the mains coming in from the road which can often pass through the structure. That would be my absolute mission based on those 60hz spikes. the 40ish and higher could be timber structure resonating. But in my electrical experience, something maybe about to go pop.

Here in NZ we have relays or contactors in the main switcboards controlling hot water supplies, some older houses Spas and Underfloor heating (ancient system - not sure if in US) but these are a common source of noise.

 

[Spocko]

This is kinda scary actually.

 

[CBM]

Can anyone post some similar graphs to show the low frequency in their house? I really don't know if this is typical.

 

[lizhuoyin]

This is a little off topic for an audio forum but I'm hoping someone with a microphone can measure the noise in their house and tell me if this chart is normal.

We live in a 89 year old house and for the last few months we have heard a low-frequency rumble sound all the time. Even with everything in the house turned off. It's the same everywhere in the house but we don't hear it outside or under the floor (pier and beam) or in the attic. It's constant and unchanging so I thought I would measure it with my microphone and REW. There seems to be a higher level of noise below 100 Hz on REW.View attachment 117246. I would like to know if this unusual or is it common in a house? It's driving us crazy and causing loss of sleep. The trace is with 1/6 smoothing.

How about refrigerator?

 

[CBM]

How about refrigerator?

That was my thought too but unplugged it and the noise was still there. Likewise furnace, stereo, ceiling fans. I'm going to flip the breaker shortly.

 

[restorer-john]

You are likely one of the people (3%) (like myself) who hear a constant low level hum. Depending on where you are or live, it can be much louder. It has nothing to do with anything in your house, I assure you. You can shut the power off completely at the power board and it is still there.

I've had it at most places I live, but the quieter the location, the more easily you can hear it, mostly at night, mostly.

https://www.livescience.com/38427-the-hum-mystery-taos-hum.html

My last house, it was very obvious at only two places in the house, this house, it's at the end where the home attaches (via steel poles- it's a timber pole hole) straight into bedrock. If I walk under the house to that part, it's even louder. I had house where it was loud enough I went to water processing plats on a nearby hill to ask them about pumps etc- it wasn't that. I even shut off the power and went outside, it was still there. Walked around the neighbourhood and could hear it at various places.