The compressors in those refrigeration units will be making a throbbing vibration, which could be resonating inside the house. A pal of mine had a nightmare with them when he lived in a house where there was a chilled food distribution firm about 100 yards away.
I started a thread about this a couple of years ago. I was off work recovering from knee surgery so home alone during the day.
Switched the electrics off etc, in the end I think it was probably in my head and was just the sound of silence - not something I was used to.
http://www.unexplained-mysteries.com/news/256820/mysterious-hum-could-be-mating-fish
Randomly remembered this mystery hum we had in Hampshire in recent years. 😆
"Once there was this kid who
Got into an accident and couldn't come to school
But when he finally came back
His hair had turned from black into bright white"
........???
If there is a rattle too look out for an annoying Irish man, probably clicking his fingers somewhere nearby..
[url= http://singletrackworld.com/forum/topic/whats-the-odd-throbbing-sound-in-my-house ]Here's my post from 2 years ago[/url], nice to see drac still doing the same old lines at the same point 🙂
Install this (or similar):
https://play.google.com/store/apps/details?id=com.raspw.SpectrumAnalyze&hl=en
then kill the power to the house and see if it changes significantly.
After killing power some things might still be fed.
Phones have power from phone line, so try disconnecting those.
Alarm may be powered differently.
As it's a semi-detached it could obviously be something through the wall. Not sure what could be running 24/7 though. Water pump to heating?
I remember reading a story about a physics professor (or something similar) who one day started hearing a new hum that would go on and off throughout the day.
He did all number of science-y tests and investigation to find it.
Eventually, he heard a new building was built and business opened a number of miles away. They had big electrical units (or similar) running. He figured out the hum was caused from the rear door to the building being left open and the sound propagating to his house through a valley.
Interesting stuff!
We have the same hum, starts at night and I cannot fathom what is causing it. Definitely not heating which has been off for months
Didn’t realize that windows attenuate higher frequencies better than lower frequencies , hence why I cannot hear it outside, but can inside. Thanks.
It's one reason. Another is that a low frequency noise source from outside is coupling to the natural resonance of the room(s) you're in. The resonance of the volume of air in the room can amplify the noise level. I expect that the noise level changes as you move about the room.
It's similar to being on a bus when it's sat idling and low frequency noise increases, although the physical structure of the bus may also be resonating in that case, as well as the enclosed air volume
I imagine I'm one of the few here who know the meaning of rt60's username 😀
I imagine I'm one of the few here who know the meaning of rt60's username
Not any more you're not, thanks to the wonders of Google 🙂
AlexSimon - Member
After killing power some things might still be fed.
Definitely, but at least it would be one thing you tick off the list.
I imagine I'm one of the few here who know the meaning of rt60's username
It means I was trying to write a report and choose a username at the same time 😀
Room nodes will also lead to variable levels in different areas of the room even with a constant source.
With the downloadable spectrometers, I would treat them with a big pinch of salt. They may give you an idea, but even with £10K+ of laboratory calibrated equipment, there is still a significant margin of error at low frequencies and phone mics are notoriously unreliable below 100Hz.
I’m pretty sure its caused by the refridgerated lorries kept in the yard up the road. Just enquired and there is no planning permission for them to keep the refridgeration units neither. - if planning is needed?
However considering their close proximity to residential properties I’d be surprised if they can get away without planning permission. Even if the planning was to only stipulate some acoustic fencing or whatever.
The local council is investigating now.
I’m pretty sure its caused by the refridgerated lorries kept in the yard up the road. Just enquired and there is no planning permission for them to keep the refridgeration units neither. - if planning is needed?
These lorries can be quite loud and I think you might be on to something there.
If it required a change of use to be a lorry park then I'd expect a noise impact assessment to have been done. However if it was a lorry park that now has noisy refrigerated lorries then I wouldn't expect any formal process has been gone through. That sort of thing happens a fair amount.
The noise barrier will have to be carefully spec'd to ensure it blocks the low frequency noise, i.e dense enough, and of sufficient height and length. It's not an usual issue so finding someone competent is unlikely to be an issue.
However, unless someone taking the measurements really knows what they are doing, attempts to quantify the low frequency noise level might not end up in your favour. E.g. "Bob" from the council can't measure anything exceeding a certain level so they regard there being no issue. I'd play very much on the subjective impact, i.e. "I can hear it, can you hear it? It's disturbing me and keeping me awake." Don't let their technical ineptitude cause you an issue*
I'd also talk to your neighbours, but due to the type of noise source it might not be those next door to you who are affected. Is there a local Facebook group you could use find out how widespread the issue is?
*I was an acoustics engineer at Nokia, then moved to be closer to family and went into "acoustic and noise consultancy", tried it, got fed up and then eventually changed career. There are very good people in the industry, unfortunately there are also some very inept people in the industry. Hopefully you'll get someone who knows what they are talking about. Happy to help out if I can
Thanks, just noticed your response. The planning permission refers to it as a transportation site. They have been keepin hgv there and there has been no problem with them. Its only when he’s subcontracted an area within the site to a refrigeration business that the problem has started.
To be honest the environmental health person hasn’t been much help. I think he’s looking for loud noises. The humming is just a hum, all the time.
Do you know of any retrospective powers the council may have to make the owner fit some kind of noise barrier?
Did you find the planning permission in the council's online planning portal? Find the original application in the planning portal and look through the documents to see if there is a noise impact assessment. If not they should have justified why one was not done, perhaps vehicle movement activity was only going to be in the daytime for example? As there is now constant activity (the hum from the refrigeration) then the owner could be in breach of conditions of the original planning decision.
The council can very much tell them to cease activity or review mitigation of emissions.
I know a lot about the technical/physics aspects of sound and have some experience of planning. From a post I saw today, rt60 seems to have a lot more experience in the planning/legislation side, so hopefully he'll return to this thread...
