Vibration HELP

[paulsherwin]

To state the obvious, have you tried earplugs?

[Nickthedentist]

Earplugs are great for HF noise, but have minimal effect at lower frequencies AFAIK. But everything's worth a try when you get desparate.

[mark_in_manc]

Hi Colin

I used to work in acoustics - maybe I can offer you some ideas.

The source of an LF noise problem might be airborne, or structure-born (vibration) - from the way you have described things, it sounds like you have a problem with the latter. To measure it acoustically, you need a mic, and to measure it in terms of the vibration of something which is then radiating noise, you need an accelerometer. Ideally your accelerometer will be fairly insensitive to acoustic pickup - so a loudspeaker with a mass glued to it is a good suggestion, as is a record-player pickup.

The response of whatever mic and accelerometer you can come up with will be seriously non-flat with respect to frequency, and uncalibrated in absolute terms - but this doesn't really matter in the first instance. I would, as has been suggested, plug it into a scope and try to find a trace at about the right frequency. You can then see how much gain there is between 'bad' and 'normal' situations, and perhaps even see the jump in level as something switches on. Perhaps this will help to reassure you that you are picking up a 'real' problem.

If it is the re-radiated acoustic signal - noise - which keeps you awake, as opposed to your bed vibrating, then there is another temporary dodge you can try as well as ear-plugs. The ears are sensitive to sound pressure (analogous to voltage), but not to 'particle velocity' (analogous to current). In a modal sound-field such as that in a room at low frequency, pressure tends to be large near to high-impedance terminations - the walls - for all modes. In the room centre, some modes have pressure maxima (anti-nodes) but many more have pressure minima (nodes).

In other words, the room centre is likely to be quieter with a 'hum' problem. Have a listen there, and if it helps, perhaps even consider sleeping with your head at the foot of your bed as a temporary measure until the problem is resolved.

I have a LF tinitus problem, so alas, none of this works for me. Oh - one last suggestion which does sometimes help me - use masking noise. Broadband noise, if you can bear it, will mask tonal or intermittent sources which tend to be more intrusive, attention-gathering and sleep-denying. FM static can work, but it may take some getting used to.

Hope this helps.

cheers
Mark

[Herald1360]

Does your building have overhead power lines?

The hum that only I seemed to notice at my parents house in the '70s eventually turned out to be from these, resonating in light winds. To make it even eerier, each line resonated at a very slightly different frequency making a sort of

mmmmmmmmmmmmmmmm.....mmmmmmmmmmmmmmmm.....mmmmmmmmmmmmmmmm.....

noise.

[Radio Wrangler]

Low freq noise is notoriously difficult to trace.
It may be merely travelling through your neighbour's house from further afield and they just don't notice it... or even coming from a different direction to appearances.

Logging start, stop and peak times might reveal a helpful pattern.

Around here, it's farmers with grain dryers going round the clock in summer.

David

[Boater Sam]

Does your neighbour have a nebulizer for his breathing problem?
Fish tank with air/water pump?
Lets hope you don't have a cannabis factory next door. Though if you do, a call to Crimestoppers should solve it!
The landlord's reluctance to assist is a problem, environmental health will enforce action.
You need to document as much as possible though.

[G6Tanuki]

Originally Posted by Herald1360

mmmmmmmmmmmmmmmm.....mmmmmmmmmmmmmmmm.....mmmmmmmmmmmmmmmm

That cyclic effect can also be caused by things like air-conditioners or fan-assisted heaters (warm-air heating?) when two or more fans run at very slightly different speeds. We had to use special self-adhesive rubber-foam acoustic damping on a couple of the big A/C units in one of our datacentres because of this effect - the low-frequency noise was disturbing people in the offices directly opposite the A/C heat exchanger outlets.

[Tyso_Bl]

Just a few thoughts from here, the times mentioned seem to indicate heating plant/boiler, on boost during morning and evening peaks, with background at other times. The old oil boiler here can sound like a small ships engine & screws at a distance, and you do get the deep fluttering rumble of the flue exhaust.

The other one is those bathroom and kitchen fans, if installed in a plasterboard ceiling it had a huge sounding board, and the combined 50 Hz from the motor and the spinning fan can produce really wierd heterodyne / strobing sounds.

[DOFFERY]

Many thanks again for your suggestions etc. I received a visit today after contacting my local councillor again. The outcome is the department concerned need a written report from an audio specialist as they have decided that is the problem!!!!

So I now await my internal clock to see if it is any different this evening/morning. I have kept a log for many weeks but they were not interested. I suggested the council might care to call on me at 3.00 am but they were reluctant!!!!

I cannot confirm just what equipment there is in the two adjoining properties as I cannot gain access & the council employee just had a look in the front room of one property some weeks ago that was it.

I still think it is a central heating problem but I will probably never know.

Will keep you advised & again thank you for your replies.

Colin.

I do wish you the very best in getting this solved. I don't like noise either but I did live very near Cambridge railway station for a few years and oddly the trains never bothered me. Must be something to do with them having a reason for the noise and knowing it will go away shortly. A bit like a neighbour telling you they are having a party and it will end at X o'clock (and of course inviting you too), that is easy to cope with.

When it come to councils, ours stopped weekend working for the noise people, that must have reduced their workload enormously!

[bikerhifinut]

Faulty thermostatic radiator valve?
I have had lots of issues with these, even the expensive types can chatter really badly and if it's the sort that HAS to be fitted on the inlet side and has been fitted on the outlet side of the radiator, then at certain temperatures and settings they can cause an almighty racket which travels right round the pipework, and the radiators become very effective transducers. Incidentally the problem became an issue when we needed a new oil fired boiler and were persuaded to go for a pressurised system with a Combi boiler. I suspect running at a higher manifold pressure made the valves more susceptible to chatter.

I hope you get a solution.

A.

[Techman]

I tend to think this is heating system related.

I live in a detached house, but a few years ago a neighbour had a 'new' gas boiler fitted which had a 'fan assisted flue', when this thing struck up it made a terrible row which I could hear in my bedroom. He was actually having a lot of running problems with this boiler, although the sound couldn't be heard inside his house, just on the outside. Luckily he did get it sorted out in the end.

[sp10mk11]

what about one of the neighbours errr growing some "special plants" in possibly the loft or a room in the house, these plants as I understand need constant heat and a warm air supply.

Gary

[m0cemdave]

Mark's advice is good (I also used to do a lot of acoustical measurements at work)

Your messages imply that the people from your local council are out of their depth, or perhaps hoping you will give up so they don't have to budget for further investigation.

I'm not sure what you mean by a "Bell" sound meter (or do you just mean one that indicates level in Bels or deciBels), but a sound level meter will not respond well to LF noise, especially when set to the usual "A" weighting used for general noise nuisance measurements.

It may be that some structure in the building is being excited at a resonant frequency by your neighbour's oxygen system, central heating pump, or whatever. A vibration meter, which uses a contact accelerometer instead of a microphone, is needed for measuring structure-borne vibration.

Repositioning your bed so that your ears are in a null, or at least away from a wall, can be surprisingly effective and is well worth a try. I used this method many years ago when I was kept awake by a noisy fridge that excited one of the resonant modes in a bedroom.

[G4_Pete]

Hi,
There are two things that cause noise from the adjacent house here

1. Power shower loud pump motor but short duration , 2 - 5 mins.

2. Water softener . These produce all sorts of noises including a timed recycle phase .

Type in Water Softener Noise into 'You Tube' - there are various explanations including some odd cartoon explanations but it may be similar to your problem.

Pete

[DOFFERY]

The latest, got home yesterday, an old clapped out fridge outside one property, hoping?
Less vibration that evening but still at low level.

Retired at 10.30pm, then blue lights flashing outside, two fire engines but little to see, they were in the other adjoining property, quiet at least, as quiet as ever, went to sleep after a couple of hours engine still outside. Alas vibration commenced from said property at 5.30am.

For a moment last night I had rather evil thoughts when I saw the fire engines!!!!

I have tried most of the suggestions by the members & as for the council, they only have sound meters, nothing seismic as the "lady" involved stated they were only for underground problems!!! I reside on a first floor flat with my business beneath, less noise there as it is more solid than the flat .

As for retiring to another room, alas the whole flat suffers from the problem, sleeping away for a few nights is my only respite, this also carries little regard with the council staff


Just to satisfy myself I have made an appointment for a specialist hearing examination asap, I have little faith in the council department if my hearing is found to be OK I may have to take legal action if possible.

Will keep you advised, I hope I remain sane enough to have a satisfactory result in the future & close this thread.

Cheers.

Colin.

[Boater Sam]

I hope you had a quiet/er Christmas!
Here is hoping for a New Year Resolution!
All my best wishes to you and yours.

[DOFFERY]

Thanks Sam, I did indeed enjoy two wonderfull nights sleep AWAY from here, back here tonight , as before heavy vibration, the last I heard from the council, they had closed the case!!!

Colin.

[Boater Sam]

I haven't seen an update about this vibration problem, was wondering if you have had a quieter new Year? Was there a solution?

[Wellington]

Me too! Did you find the source of the noise/vibration, Colin?