Hi everyone Newbie needs advice on how to record low frequency noise.

I just tried generating 6.5, 8.10 and 12.5Hz tones and then re-recording them. 6.5 and 8 I can turn up loud and I think I'm just aware of them, while 10 and 12.5K are a sort of puttering noise.

A shire mic (an Sm63 condenser omni) visibly hears them and appears to be able to record them, to0. I did not believe it would, but it does.
 

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I think the problem is that the OP doesn't really know what Hz he's hearing. If he has an audio system with a sub, and a way to play some tones, he might be able to nail things down so that we can better address this. Also, it's possible that his room has nodes that reinforce certain tones. At the right frequencies, you can certainly get resonances.

If he knows where the sound is coming from, it should be a simple matter to go to the place when he hears the sound. As far as I know, there's not a practical way to "beam" low frequency noise to a particular spot to target someone. You have to go much higher in frequency to be able to control the directionality, like into RF/Microwave ranges.
 
TalismanRich said:
I think the problem is that the OP doesn't really know what Hz he's hearing. If he has an audio system with a sub, and a way to play some tones, he might be able to nail things down so that we can better address this. Also, it's possible that his room has nodes that reinforce certain tones. At the right frequencies, you can certainly get resonances.

If he knows where the sound is coming from, it should be a simple matter to go to the place when he hears the sound. As far as I know, there's not a practical way to "beam" low frequency noise to a particular spot to target someone. You have to go much higher in frequency to be able to control the directionality, like into RF/Microwave ranges.
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I present as exhibit A
"One enviromental officer who is susceptible to low frequency sound could hear a noise, but i ended ujp having an argument with him as he said the noise is coming from miles away. I said no, its only when i'm in the house i'm being targeted."
 
The trouble here is that collecting evidence is a real problem and without it you cannot move forwards. The wavelength of this noise is so long, you cannot localise it, and it will almost certainly be transmitted via the structure more than the air. With higher sounds they get displaced in time so wavefronts cancel or combine and over 1K or so, it changes as you move about, but this low frequency noise cannot do that, it’s just present or absent.

You should be able to get something done, but it appears you alienated the one person who believed you and could hear it. Of course he thought it sounded like miles away, LF does not have directionality, hence why we don’t notice a sub is in a different place to the speakers, so the remainder of the people think you are potty.

I tend to think he has something mechanical he turns on. If you cannot record it, or locate it, or even prove it’s him, then sadly, there appears nothing you can do, technically, at least. After all, it’s totally possible he cannot hear it either!
 
Bones00 said:
Hi rob thanks for reply, he is a very clever guy, who by the way is very computer and tech minded. I think he has some sort of speaker which emits a very low noise in which when i have had people round can not hear it, but i can. all i know its low very low i can feel my ear drum moving when hen turns the volume down or intensity. As for the 6hz i phoned cirrus research and they said the microphone can go down to 6.5hz. So why didn't it pick it up. He changes the sounds all the time from very bouncy sounds to long rumble sounds. I have had major problems about this problem. I come home from work nothing then once night comes its starts...When he knows someone in the house noise goes off. When they leave it starts again.. during lockdown i got hammered by the noise with know body to turn to. I don't understand why it does pick it up...I think is some kind of power full guitar speaker, but i'm not sure. As soon as he knows people are about i e, postman, police, environmental health workers noise goes. Even with the trojan 2 nuisance noise meter i'm told nothing picked up. I hired a CR171A noise meter from cirrus and i have one recording, but even with that i can't seem to play the sound back. As i set up the noise meter i hired i could hear the sound but the software graph on the meter wasn't bouncing to the sound the microphone even picked up my stomach rumbling, i saw the graph move but as for the low frequency sound nothing..I know the sound exists, ive been tested for titanus and i'm fine. The air goes very thick some times and i can feel the waves....I'm baffled. tbh..Thanks for response it is helping tbh. One enviromental officer who is susceptible to low frequency sound could hear a noise, but i ended ujp having an argument with him as he said the noise is coming from miles away. I said no, its only when i'm in the house i'm being targeted. I have snuck in a few times and heard nothing zipp. zero, then as soon as he knows im in bang the noise starts...Like a rumble very intense, very low.

Regards Chris
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Totally confused. Why would your neighbour do such a thing and why doesnt it affect him?
 
The second part is easy. The majority of people cannot hear it. If you create a 6.5Hz tone, and replay it on a system where you can see the speaker cone - you can see it, you can feel it on the back of your hand - but most people cannot hear it - or perhaps maybe they are hearing it but their brain cannot process it as 'sound' - so they ignore it. It my studio, I think that what I may really be hearing is the noise of the speaker cone trying to reproduce it. You can easily see 6.5Hz as distinct cycles of the cone. It's not a musical tone, so I wonder if that is why when the authorities were asked to listen for a noise, they missed it (bar one, and this person was lost in the disagreement, leaving none)

If you have a piledriver you feel it through your feet. Closer to, you seem to hear the harmonics which go higher. Here, the fundamental is below our ability to hear it as sound. It's a flutter of wind - a sequence of wave fronts of low frequency - it's not noise in any version we can hang onto.

The nearest thing I can cling to for me is infra red and ultra violet. You can feel the heat from those outdoors infrared heaters, but all you see is a weak red glow, but ultraviolet response seems quite individual. I used to do lots of those black light shows - the ones where performers where black, against a black background in a venue wit a little h no ordinary lights on. You light the space with UV light and certain materials and paints fluoresce. The snag seemed to always be some people would complain that they could see the performers, while I couldn't. Others would say how bright and vibrant the colours were, others would say how dull everything was. UV and IR are just outside our ability to perceive them, but we all differ a little on the cut-offs. Our poor friend here seems very susceptible to LF energy and finds it not just annoying but disturbing. It's a fact, and I feel for him, but I don't see how he will ever convince those with power to fix it, and he cannot collect any evidence as to the source. I know my wife steals my Pringles, but until I actually catch her in the act, I'm not even going to mention it because I can't prove it.
 
Right i can now reply.
1. I confronted him, he ran off down his drive like the coward he is.
2. I have balls, i have fought for my country....
3. Hew hates me and wants me to move as i found out he is behind some dodgy things.

Thankyou Rob some one with a bit of common sense on here.
Nightmare situation trust me.
 
Have you tried asking your neighbour what the source might be?

I have another suggestion - Tinitus.

For ages I could hear distant low frequency rumbling, while trying to get to sleep.
I even went downstairs and stood outside the house to work out where it was coming from.
Occasionally, you can hear trains shunting miles away, and helicopters, and we also get the army firing shells at night 30 miles away.
I suspected the metal foundry working 24/7 about a mile away.
I never did get to the bottom of this particular rumbling.
Then, when I was working away from home for a job, I stayed at a caravan park.
Guess what? I could hear the same rumbling, so it couldn't have come from where I live.
The conclusion is that the rumbling is in my head.
I do have permanent high frequency ringing, which I just live with, but it seems there are low frequencies too.
This probably started after attending loud concerts, that left my ears ringing for two days after.
I do have very good hearing, but the tinitus is there in the background.
 
Slouching Raymond said:
I do have very good hearing, but the tinitus is there in the background.
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It is probably normal. Everyone I know whose older claims they hear a 8-10khz note . I worked in garages with air tools , rebuilding fleet transmissions for years.

When i get home, I either play guitar, or put on some phones. The whole world could explode, I wouldnt have a clue. Probably end up just turning up the jams as Im cutting out..
 
Not Tinitus ive been tested..

STOP WITH GUESSING, OR EXCUSES, ITS SOME SORT OF VERY LOW FREQUENCY SPEAKER OK, REALLY LOW.
Regards
 
Bones00 said:
, ITS SOME SORT OF VERY LOW FREQUENCY SPEAKER OK, REALLY LOW.
Regards
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Come on , man. Have you asked him? He said 'I built this ultra low freak directional sonic emitter...and I only shoot it at you?' ..is this what Im to believe...
If it was a subwoofer other people could hear it too..
Go to him. Politely ask him if you two, can address this particular issue. He ran off ..makes no sense. Why didnt you handle the situation? If you brought it to his attention and he walked away from the civil matter. File a Grievance with police/township /housing association, and take him to civil court. There you are entitled to an investigation leading to discovery and most likely satisfaction.
 
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Shit man, everytime i went at it cause of my garbage can lids blowing off, or sticks in the yard. The police came and we went to jail. Judge had to sort it out. Lady next door would hear the guy say he was going to kill me. And she called the police.

Ran away?

Now, the neighborhood is dead silent. Nobody will speak to each other. Nobody looks at each other. No kids play in the area...Perfect.

Now I have new garbage cans that have a lid attached by a hinge.
 
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Kind of funny.. He said ' If you were my kid Id beat you to death with a bat'

it was witnessed, and recorded but the recording was not admissible. I didnt get his permission to record him...

They didn't take it as a threat on my life..It was a supposition..
 
Bones00 said:
Not Tinitus ive been tested..

STOP WITH GUESSING, OR EXCUSES, ITS SOME SORT OF VERY LOW FREQUENCY SPEAKER OK, REALLY LOW.
Regards
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One issue is that we aren't there, so we can't really experience what you are hearing. We HAVE to guess. However, if there is sound, it can be recorded. If you have a microphone that reads down to 6Hz, then anything you can hear can be captured. Get a signal generator and determine first, what the frequency is. Saying it's a low frequency could be anything from 16Hz (the fundamental of a 32ft Pipe Organ) to 40 or 50Hz (low E on a bass guitar). Anything below that is subsonic, more felt than heard unless you have absolutely superhuman hearing. The main rotor of a helicopter is typically in the 4-8Hz range, although the tail rotor will be higher, like 30 or 40Hz. I hear cars driving down the street with their 15 inch subs and 1000watt car amps with the rumbling hip hop music. I've seen the mirror in my car vibrate from a car two rows over.

A computer or synth can easily reproduce a low frequency sine wave. Find one and determine what the frequency really is, not a general "low' description. Then you can work on documenting it, including level.
 
Bones00 said:
Not Tinitus ive been tested..

STOP WITH GUESSING, OR EXCUSES, ITS SOME SORT OF VERY LOW FREQUENCY SPEAKER OK, REALLY LOW.
Regards
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I'm calling bullshit as you clearly have no idea of the physics of this. There would be so much more in the way of other resonances if it was local in the same building. So no more guessing from me but seek answers elsewhere. This is not the place for tin foil hat stuff except maybe in the primetime forum.
 
.I'm trying to find how to record it ok..Simple advice.. Please...Yes i have know idea of the physics of this, thats why i'm asking ok, i'm only telling whats going on, i don;'t need abuse or tin foil hat shit....What ever that is...I just need to know how to record it, and how i can get my hearing tested to very low frequencies ok.
 
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