How to measure footstep vibration and noise?

I am on the board of a NYC co-op apartment. Residents of the building have ongoing issues with excessive noise and vibration resulting from inadequate floor coverings and unrestrained activity of children in apartments on the floor above. Some noise in communal living is expected. However, there are situations which seem out of control. What, if any, equipment is available that could provide an effective measure of this type of impact/vibration noise so that our residents are not forced into situations where one person's word is pitted against another's?

I know very little about electronics so simple explanations would be extremely helpful. Would a seismometer be useful? Something using an accelerometer? It doesn't seem like an ordinary noise meter would register the problem when the jarring vibrations of the impact are frequently more the issue than the actual noise. And just how prohibitively expensive would such equipment be?

Thank you.

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vze3j5ge
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Whilst an accelerometer or a geophone could be used to measure impacts and vibration, you would have a problem calibrating it so that you got data which actually meant something and could be used for enforcement purposes.

I once interfaced a geophone to an AVR and transmitted the data to a PC via RS-232. The total cost was about $100, IIRC. I still have the hardware somewhere.

Leon

Reply to
Leon

Agreed. And while there are probably numerous audible noise standards around, subsonic frequency noise is probably much less well characterized.

Using an inexpensive seismometer or accelerometer sensitive in the 1Hz to

20Hz range would let you make comparative measurements; in a cooperative environment it may help with the skepticism, but if people are just going to refuse to change their behavior no matter what a technological solution doesn't help much.
--
Tim Wescott
Control systems and communications consulting
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Reply to
Tim Wescott

Yes, calibration would be an issue, I'm sure. And a refusal to change behavior, as Tim says, won't necessarily be helped by technology. We are currently just trying to see if there is any way to measure at all. The hope would be that it might give the Board some slight leverage for mediating these situations if the offenders can be shown that the complainants are not just overly-sensitive troublemakers but have a legitimate, measurable grievance -- or, conversely, if the complainants can be shown that the vibration is no greater than that in any other apartment.

I'll do some research on geophones. It's hard to find sites that are geared to the non-expert.

Your responses are much appreciated.

Reply to
esmith591

On the same floor as the noisy children, rent an apartment to a registered child molester ?:-)

...Jim Thompson

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| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Jim Thompson

Reply to
esmith591

** Have you even tried and SPL meter yet ???

The sort of noises you allude to ARE mostly in the audible range - ie footsteps on smooth surface floors will be heard in the apartment below by direct transmission and impacts on the same floor will shake the entire floor at some low but audible frequency.

Any decent SPL meter allows testing with a flat response or " C curve " weighting, both of which will show low frequency noises very clearly.

IME - the use of carpets with foam underlay is essential in apartment blocks, on all living area floors except the very lowest level one.

..... Phil

Reply to
Phil Allison

I'm not sure a geophone is the way to go these days. I bought an accelerometer from Sparkfun and geek that I am, found it fascinating.

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The signal conditioning is right on the chip. I had mine connected to a scope, but it seems to me you could drive a soundcard.

Of course, I'd probably find a geophone fun too. You can get them in old seismic detectors used by the military. Murphy has them, though you can always get Murphy's stuff at a third the price if you poke around:

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Reply to
miso

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An accelerometer PCB would be difficult to couple efficiently to the building structure without a lot of extra work. Geophones usually have a shaft that can easily be attached to the floor.

Leon

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Leon

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Actually the geophones have a spike to hammer into the ground.

The sparkfun accelerometers are on PC boards. You could mount the board to a plate using spacers, then mount the plate to the floor.

The deal with the geophone is you probably need signal conditioning. I see them being like a moil coil phono cartridge, so you might be able to steal circuits for that application, but it's all very low level stuff. There is a LT1028 design for moving coil preamp design, though you need to remove the RIAA equalization circuit.

Amazing, there are no geophones for sale on ebay. It must be a slow week. I found a few on the net here:

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I think you can do better than that design. The LT1028 and a few others are very quite op amps.
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Reply to
miso

Wow! So much help! I'll need to do some more reading and research, because I don't think I understand everything you've said, but I'm very grateful for for all the suggestions and the links.

Thank you!

Reply to
esmith591

You can buy a sound level meter from radio shack that has a 'record maximum' feature. Duct tape it someplace safe, and see what it comes up with.

You could also use a PC for this. There are audio analysis programs available on the web that will record. If you have a safe place to put it, that is probably the easiest way to go. Audigy is a freeware sound client that would work for this.

Regards, Bob Monsen

Reply to
Robert Monsen

"Robert Monsen"

** The f****it OP has posted his same message on other NGs - and got the same answer re the use of an ordinary SPL meter to quantify the problem.

He has so far studiously IGNORED all of them.

Also, the OP has provided no information of the nature of these suspended floor - are they concrete slabs?

What size / area are they?

Perhaps they are unusually big for a residential premises.

..... Phil

Reply to
Phil Allison

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I think you means Audacity

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It seems you can set the sample rate as low as 1Hz. Probably 1kHz would make sense for this application.

Reply to
miso

Yes, I did. Thanks for the correction.

Regards, Bob Monsen

Reply to
Robert Monsen

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