EWJ Dec 2023 - Journal - Page 83
The following were the items which rendered the report inadequate, unreliable, and non-compliant with
BS4142, meaning that the report and its +9 rating
should not have been accepted as admissible by the
Court:-
bank is intermittent and completely random and in
this situation BS4142 states that a longer sample is required to characterize it (7.3.9). The Standard goes
on to say that "it might be necessary to investigate the
sound over relatively long periods to select an
appropriate representative measurement time
interval". The e3p report referred to above took measurements over several days due to the intermittent and varied nature of the specific sound source.
Compare that to the expert in this case who carried
out measurements for a mere 1hr 6m (15.53 - 16.59).
Not only that, these readings were taken on a late
Monday afternoon, probably the least busy time for
public use of the facility. The busiest days are Thursdays (bin collection day from residences), Fridays and
Saturdays (holiday cottages changeover days) and
Sundays. Also, because the expert has failed to investigate over a longer period, as stipulated by the Standard, this precluded him from recording the
considerable amount of unauthorised business use
that was occurring at the bottle bank, often involving
dustbin loads of deposits at a time. On a regular basis
a huge dumper truck from a local farm holiday complex arrived with two full dustbins of bottles loaded in
its bucket and tipped from a great height into an open
bin generating a dB level far in excess of any reading
in the expert's report (Fig. 2). In summary, this aspect
of the expert's report is grossly inadequate in terms of
time allocated and a totally unrepresentative and
unreliable snapshot of its usage.
(1) misrepresentation of the height of the hand-held
sound level meter
The expert claimed the height to be "approximately
1.2m" (clause 4.5.11) in order to infer compliance
with the measuring height requirements of BS4142
(1.2 - 1.5m) - this is completely false. The meter was
resting on top of a lidless wheelie bin which measured exactly 1.0m in height, potentially rendering
the results at Table 2 of his report
inadmissible.
(2) simulations of the large bottle drops
The expert uses the term "simulation" himself in the
report (clause 4.5.9) - confining a large quantity of
bottles within a bag and re-using it 12 times over in no
way replicates the real life noise characteristics of a cascade of glass being tipped from a crate or trug. He also
claims that when performing individual bottle drops
he used force - from my observations they were simply let go. This in no way mirrors use by members of
the public, many of whom take great delight in smashing their bottles as forcibly as possible. Of the 30 sound
recordings on which the report is based only 6 (20%)
are real life deposits by members of the public. It is
worth noting that the simulations of the large bottle
drops and imitated individual drops (80% in total) was
only necessary due to the woefully inadequate time allocated to the measurement of the specific sound
source (1hr 6m). The Oxford English Dictionary defines simulation as "the action of pretending; deception", which is what appears to be occurring here.
(5) insufficient time allocated to the measurement
of the background sound level
BS4142 advises that the time interval (T) of the
background noise measurement should be sufficient
to obtain a representative value of the background
noise level. At 8.1 it states that "it is important to ensure
that values are reliable and suitability represent both
the particular circumstances and period of interest".
At 8.1.4 it states that "to obtain a representative background sound level a series of either sequential or disaggregated measurements should be carried out for
the period of interest, possibly on more than one occasion." In the Standard the emphasis is on "the reliable and truly representative." Unfortunately the
expert's measurement of the background sound level
was neither of these. The background noise profile predominantly consists of road traffic noise. Road
traffic within the village is highly seasonal and volumes
vary according to the time of day with light traffic in
the early mornings and late evenings. The assessment
was carried out during peak holiday season and at a
busy time of the day. In addition, on this particular
day, as often happens, there were large tailbacks on
the northbound A1 resulting in traffic diverting off
onto the coast road which passes through the village there could not have been a more unreliable and unrepresentative time to record the background sound
level. The e3p report measured background sound
levels over a period of four days (Friday, Saturday,
Sunday, and Monday) to ensure reliability and representativeness as compared to 1hr 31m on a single
Monday afternoon by the NCC’s expert.
(3) absurd impulse noise character penalty
The expert applied a +3 penalty for the intermittent
nature of the specific sound source which is patently
correct. But he only applied a +3 penalty for its impulsive nature which means, that in his opinion, the
impulse noise was only just perceptible from the nearest receptor's garden 18m distant. These receptors
(@mp1) supplied a witness statement for presentation at Court. They state - "the noise of the bottles
being emptied is loud and we regularly feel it vibrating through our floor in the house. When we are outside in the back garden it is a frequent noise
throughout the day, but it can also be heard inside the
house too. It isn't a nice noise." Another receptor
whose garden is 70+m distant from the facility testifies that "the protracted sound of smashing glass at
high decibels is a frequent nuisance." For the sake of
comparison the e3p expert referred to above saw fit to
apply a + 3 impulse noise penalty for receptors in excess of 200m away! It is patently obvious that the impulse sound is more than "just perceptible" - from the
evidence of the nearest receptor it can only be described as highly perceptible, warranting an absolute
minimum penalty of +6, or more justifiably +9.
(4) insufficient time allocated to the measurement
of the specific sound source
The specific sound source emanating from the bottle
EXPERT WITNESS JOURNAL
81
DECEMBER 2023