Natural Science Forum / Physics / Acoustics / December 2008

I'm sure the real experts will chime in soon enough, but it seems to me a
standard $50 Radio Shack SPL meter would do the job. I understand that some
of the noise is felt as much as heard, but it still should register on an
SPL meter. The larger question is not how to measure the noise, which you
already know is intrusive, but finding a solution that doesn't cost $15,000
per apartment for new floated floors etc.

--Ethan

With a general move away from fitted carpets and towards hard floor
coverings there has been a great increase in noise problems in apartments.
Often leases or contracts require people to fit carpets but are ignored - I
suggest this is the first point to check.  Where hard floor finishes are
part of the building design, architects should incorporate resilient
isolation, but even if the architect complies with the building code there
can easily be interference with neighbours if there are young children in
the upper apartment.

There are two questions here: one about building construction and carpets,
and the other about people's behaviour.  These aspects are addressed by
different measurement methods.

Building construction is tested by making a standardised impact with a
tapping machine, and measuring the sound level in the room below.  The
tapping machine noise is not much like human footsteps (imagine a lot of
cats wearing clogs) but it is standard and we know how to interpret the
results.

The other aspect is the actual noise and vibration.  Modern sound level
meters allow noise to be measured and the actual sound to be recorded over
long periods, and this is often necessary in noise from neighbours disputes.
If there is serious disagreement the meter can be put in a locked case so
that it cannot be interfered with.  It is of course also possible to measure
vibration, but this is not usual, because if the vibration from footsteps is
a problem, the noise will usually be a worse problem.  For vibration, you
have to think about making sure that you are measuring it from the right
source, and not from local footsteps, traffic etc.  Also it can be more
disruptive because you really have to access the main floor slab without any
soft or resilient covering.

In both cases there is a problem in interpreting the results.  For the
building there are probably no statutory requirements unless it is new.  For
the actual noise and vibration, it can be difficult to agree on what is an
acceptable level, although if it is bad enough this could be fairly obvious.
There are a number of possible guidelines for acceptable levels, but I think
there is nothing definitive.

It looks to me as if you will need professional consultancy.  But before you
get any measurements done, do make sure you know what to do with the
results.  Otherwise you could end up with a lot of expensively acquired
data, but no agreement on what it means and what should be done about any
problems.

Finally, with noise from neighbours the solution is rarely just technical.
I have come across situations where a technical fix solved the problem even
though the neighbours were still not on good terms, but this is rare.
Usually to get a satisfactory resolution, it is necessary to come to some
understanding with the neighbours, even if you have to agree to disagree on
certain points.