Low frequency (maybe infrasound) between houses-expert advice needed 2

[Helpmeplz12341234]

Hi

Thank you for looking at my post, I appreciate any input and am looking for some expert advice on my situation.

Regardless of this is on purpose or not I hope we can focus on the details below. My primary concern is if something is attached or touching my house

My neighbour is in a wooden house and I am next door in a cast concrete house, there is about 1 meter between us and both of our first floors are partly underground.

There is an excruciating low frequency noise coming from their house to mine and I don’t know how. As their house is wood I cannot see how they can do it without disturbing their living too but it is happening. Times are irregular and I have had everything checked in the house already (water/elec/air con etc...)

One important thing to note is my neighbour is a professional acoustic/sound engineer so this is why I am asking for your input

It is hard to record this low sound so I guess it’s under the hearing spectrum so maybe it’s Info or really low frequency. When I press my ear to the window I can hear it outside, I can’t hear through the concrete wall. When it is on my bed feels vibration when I am in it.

My only guess is a directional speaker in his underground floor with low level frequency coming out but I don’t know. Also if my bed vibrates from it would that mean whatever is making this noise be touching my house somewhere and it’s going through the structure.

The sound is loud and my ears are ringing from it. I have had my hearing checked out also.

Any input or questions are appreciated, thank you for your time

 

[Strong]

You have three broad issues:
1) The neighbor who may (on purpose or not) or may not be making the noise.
2) The acoustics of sound propagation including generation (source), path (airborne, soil, or linked structure), and receiver (your detection and annoyance).
3) Mitigation of the sound/vibration level and annoyance.

It is complicated problem technically and possibly by your relationship with your neighbor.

Identifying and quantifying the sound source is the best place to start. Are you in the USA or someplace else on the globe?

Walt

 

[Tmoose]

A glancing 2nd hand experience of an I-phone vibration app looked promising.
This suggests it may be able to process signals and identify frequencies down to 5 Hz or so.

https://apps.apple.com/us/app/vibration-analysis/id817385888

I think you should almost be able to "count" 5 Hz "vibrations" when you are lying in bed.

Conversely, if you are really "hearing" a sound with your ear not quite touching the glass, and not "feeling" mechanical vibration at the window, that suggests the frequency is a bit higher, > 15 Hz.

This mechanical reed tachometer supposedly reveals single frequency vibration as low as 14 Hz or so.

https://www.amazon.com/Briggs-Stratton-19200-Tachometer/dp/B0044AV5VK

 

[Helpmeplz12341234]

Thank you both for the replies.

100% it’s the neighbour, I’m a foreigner living in an Asian country that does not like foreigners and they want me out of the neighborhood unfortunately. I suppose what I am really looking to find out is, is there something attached to my house via them or is it most likely from their place through the ground/air to mine. I know I won’t win this battle but I would like to find it if it is touching my place, I already discovered a hidden motion detector he has pointed at my bathroom (I have a big glass door there)

The country I am living in has minimal law against this type of frequency (more about loud noises like music) I also recently discovered there is companies here that do this yep of thing called “revenge companies”

I am moving but I want to see how much my privacy has been violated

 

[Strong]

Unless you can see a rigid pipe or electrical conduit between the two dwellings, then the connection is by ground/soil or airborne. Ground vibrations can be complicated by common bedrock or high water table (water level in soil) that can improve ground vibrations transmission. If the sound/vibrations are made electronically and are not from music, then you are under attack! I guess your choices are make friends with neighbor, get police/legal assistance, move, or get even by making your own noise.

Dan, the Apple iPhone app measures vibration and not sound. Sound/audio apps are available, but a good microphone is needed to get to low frequencies.

Walt

 

[Helpmeplz12341234]

I don’t there is, when there was scaffolding around my house for a month recently there was no noise. I noticed some tampering with my outside water mains and was thinking it might be through that pipe but just my thought

I want to ask, what is an example of the equipment if it is electronic. (Not music)

 

[GregLocock]

If I were building a low frequency ground thumper it would merely be a large mass on a spring, with a voicecoil to drive it (same as a speaker) However it would be deafening as you got closer to the source. A low frequency infrasound generator is often a swinging door with a linear actuator. Same problem applies, it will be much louder nearer the source.

Cheers

Greg Locock


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[Helpmeplz12341234]

This is the thing that is stumping me, he is in a wood frame house with wife and kids. How can he do it from his house which is why I think it might be outside his out between us. If it was in his house it would disturb him too which is why I thought it could be a linear speaker.

 

[GregLocock]

What is a linear speaker?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[Helpmeplz12341234]

He is left I am right

 

[Helpmeplz12341234]

Speakers sound comes out in a Triangle-esque shape and spreads, these type of speakers have the sound coming out in one direction(forward) so if your in front of the speaker you hear it, step to the side you won’t

 

[3DDave]

Disturb him? If it is to get you to move that to him is a sweet sound.

Anyway, I'd get a car mechanic's stethoscope. They have a rod on the end rather than a cone and are used to find engine noises inside engines through direct contact. They are inexpensive ($20 USD or less) and otherwise useful, so it's a handy tool. Then you can listen directly to the house, to the dirt, to his house if you aren't too obvious about it. Check the dirt at various distances to see how the sound level drops off to find the origin.

I had an intermittent loud hammering sound for a while. It turned out to be the gas meter in the basement; one of the pipes going to it was barely touching ductwork and, in the winter when gas demand was high and the basement and meter were cold they would touch, allowing some minor vibration in the meter to be efficiently turned to sound from the wall of the duct. Upstairs it sounded like a jack hammer going. In the basement the sound was confined inside the duct and it was a slight rattle.

 

[hacksaw]

You're dealing with plumbing noise common these days, in all hosing where the pulsating shower heads are common.

What part of China are you are in? it is a remarkable country,
where even small cities can have ten million populations.

 

[Helpmeplz12341234]

It’s Japan and all pipes, heating, water etc... were checked professionally.

@3Ddave good suggestion, I thought of it before but he turns it off when anyone is near my place so it won’t work. Even when a pizza is being delivered it turns off for those few minutes until they leave. Reason is, if I called the police about the noise they have to hear it in my house first before talking to a neighbour. Mental

 

[hacksaw]

You've raised several questions. The image suggests that you have AC units in the alley. They can be noisy, is the compressor support pads are wornout.

Just how are you monitoting the status of this sensor in real time?

 

[IRstuff]

What's the thing in the upper right corner? It looks like a tankless water heater?

It looks like your neighbor has THREE(?) AC units? Note that when multiple fans are running, there are often beat frequencies that get generated; perhaps that was the intent of your neighbor.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[BrianE22]

Just to be sure, I'd turn off the power coming into my house to make sure it is nothing in my house causing the problem.

 

[hacksaw]

"There is an excruciating low frequency noise coming from their house to mine and I don’t know how. As their house is wood I cannot see how they can do it without disturbing their living too but it is happening. Times are irregular and I have had everything checked in the house already (water/elec/air con etc...)

One important thing to note is my neighbour is a professional acoustic/sound engineer..."

Perhaps you should ask your neighbor, as he has the equipment needed to detect and track down you complaint!

 

[Helpmeplz12341234]

What can I do to check that water heater?

 

[Helpmeplz12341234]

This is 100% neighbour not your suggestions. Everything was checked, when their aircon is on it barely makes a sound in my place, the noise started late at night usually just after I turn off my last light. It’s every night b it there is never any noise when someone stays over. It goes on and on but it is neighbour on purpose and I’m just hope to find anything that is violating my place.?the noise can vary from reving sound to banging to flat tone (all low frequency) every morning my ears are ringing like crazy and pain