Low-frequency Hum in my house.

[MrPeabody]

If there is low-frequency fluctuation in water pressure, plumbing will respond if there is air trapped anywhere within. If you tried everything else you can think of and can't pin it down, it might be worthwhile to shut off the water outside the house. Similarly with natural gas, if you have natural gas, which isn't liquified but is highly compressed and fluctuation in the gas pressure can cause those pipes to vibrate. Also shut off the hot water heater and leave it off for a day to allow it to reach room temperature, to see whether this does anything.

Whatever it is I hope you find it.

 

[CBM]

If there is low-frequency fluctuation in water pressure, plumbing will respond if there is air trapped anywhere within. If you tried everything else you can think of and can't pin it down, it might be worthwhile to shut off the water outside the house. Similarly with natural gas, if you have natural gas, which isn't liquified but is highly compressed and fluctuation in the gas pressure can cause those pipes to vibrate. Also shut off the hot water heater and leave it off for a day to allow it to reach room temperature, to see whether this does anything.

Whatever it is I hope you find it.

Thank you. I turned off the breaker and the noise was still there. We could hear it and my RTA app on my phone showed the same 45 & 80 Hz peaks. I tried to get video sound but there was just a hiss. Next is the water.

 

[RayDunzl]

Where do you live?

 

[CBM]

Where do you live?

In East Texas. A 1930s neighborhood in Tyler.

 

[Wombat]

Neighborhood pool pumps?

 

[CBM]

Those usually whine. Plus we can't hear it outside.

 

[RayDunzl]

In East Texas. A 1930s neighborhood in Tyler.

Stick your mic out a window and see what you read.

 

[CBM]

Stick your mic out a window and see what you read.

LOL. The windows don't open on this old house. I'll try a door.

 

[CBM]

Stick your mic out a window and see what you read.

Inside

Outside

 

[RayDunzl]

Is that "inside" now, or a copy of earlier?

 

[WilliamF]

Did the sound appear after the rather extreme cold spell we had last month?

 

[spacevector]

OP, you used 'we' in the first post but I want to confirm that you and members of your household are all hearing it and not just you?

 

[CBM]

Is that "inside" now, or a copy of earlier?

It's a new one. I took a measurement inside and walked out the door nearby for the outside.

 

[CBM]

Did the sound appear after the rather extreme cold spell we had last month?

We heard it before the freeze.

 

[CBM]

OP, you used 'we' in the first post but I want to confirm that you and members of your household are all hearing it and not just you?

My wife and I and some visitors.

 

[RayDunzl]

It's a new one. I took a measurement inside and walked out the door nearby for the outside.

I would have expected the outside and inside to have similar frequency peaks.

Of course, it keeps changing.

Outside noise does that as different sources find a path to you as the atmospherics change.

At Audio Buddy's house, who lives 1/2 mile from a busy expressway, on an otherwise quiet evening, while standing on the porch, sometimes every vehicle passing by is heard, and other times we hear none at all, depending on the microclimate of the moment.

https://rosap.ntl.bts.gov/view/dot/40318/dot_40318_DS1.pdf

 

[Don Hills]

I have no suggestions for the source of the sound, just a suggestion for anyone who might find themselves with a requirement for using a smartphone for recording. Smartphone microphones aren't optimised for full-range recording. I use a cheap lapel microphone with a smartphone plug - it has the same plug as a smartphone handsfree earplug / microphone set. They are also available with USB-C plugs if you have a recent phone with only USB-C. It has wider frequency range, more sensitivity and lower hiss than the built-in microphone.

 

[Blumlein 88]

Do you have 12 foot ceilings thru out the house. or is the main floor about 12.5 feet over a basement? The 44 hz corresponds to something resonating at 12.5 feet spacing or a 25 ft wave.

I have a long listening room and the longest dimension is not quite 34 ft. So it has a resonance of 17 hz. You can see in noise peaks of 17 hz, 34 hz and 51 hz. I don't have any particular source at any of those frequencies, but I take it low frequency pinkish noise excites those resonances. Those peaks grow higher when a train rumbles down a nearby track because it injects more random noise into the structure for it to resonate.

Another possibility is AC ductwork running down the center of your house and each vent branches off going 12 feet or so to the vent and all those ducts the same length resonate. If so it should be worse with AC running, but will still resonate at low levels with the AC off.

 

[rdenney]

I still think you have a motor running in the house you don’t know about. Do you have a sump pump in your basement? A condensate pump in your air handler? A radon mitigation fan? An attic or laundry room ventilation fan? A leaky Sleep Number mattress? A muffin fan with a bad bearing on the NAS stuck in the office cabinet? All of those have made low-level mystery roars for me at one time or another. If it sits on a hard floor or is screwed to a wall, it can resonate the whole structure.

This can get weird. The ceiling fan in our den was an old cheapie installed by the previous owner (and we moved here 19 years ago), and the rubber damper ring rotted and the fan-blade assembly dropped to the floor. I put it out on the porch while I looked for the part (which I never found). Several weeks later, my wife complained of a low-level noise. Took an hour to localize it. When the blade assembly fell, it pulled the pull switch and the fan motor was happily spinning away, turning only its narrow mounting hub, too quiet to be obvious but not silent.

Rick “who has heard several of these through the pillow at night, at least before CPAP” Denney

 

[Somafunk]

Any fracking or other such industrial sites nearby?, given the perfect weather and atmospheric conditions sound can manifest in very strange ways.

Failing that I guess the logical conclusion is your house is built on an Indian burial ground, I’d smash your tv’s up just to be safe and beware of creepy preachers skulking around.