Western Australian Current Regulations Western Australian Current Regulations (1) In this regulation
and in regulation 7 —
impulsiveness means a variation in the emission of
a noise where the difference between L A peak and L A Slow max is more than
15 dB when determined for a single representative event;
modulation means a variation in the emission of
noise that —
(a) is
more than 3 dB L A Fast or is more than 3 dB L A Fast in any
one‑third octave band; and
(b) is
present for at least 10% of the representative assessment period; and
(c) is
regular, cyclic and audible;
tonality means the presence in the noise emission
of tonal characteristics where the difference between —
(a) the
A‑weighted sound pressure level in any one‑third octave band; and
(b) the
arithmetic average of the A‑weighted sound pressure levels in the 2
adjacent one‑third octave bands,
is greater than 3 dB when the sound pressure
levels are determined as L Aeq,T levels where the time period T is greater
than 10% of the representative assessment period, or greater than 8 dB at
any time when the sound pressure levels are determined as L A Slow levels.
(2) In
subregulation (1) —
L AeqT means the equivalent continuous sound
pressure level in decibels (dB) using the “A” frequency weighting
characteristic, as specified in AS IEC 61672.1‑2004
Electroacoustics‑Sound level meters Part 1: Specifications,
determined over measurement time period T with sound measuring equipment that
complies with the requirements of Schedule 4;
L A Fast means the reading in decibels (dB)
obtained using the “A” frequency weighting characteristic and the
“F” time weighting characteristic, as specified in AS IEC
61672.1‑2004 Electroacoustics‑Sound level meters Part 1:
Specifications, with sound measuring equipment that complies with the
requirements of Schedule 4;
L A peak means the peak sound pressure level in
decibels (dB) obtained using the “A” frequency weighting
characteristic, as specified in AS IEC 61672.1‑2004
Electroacoustics‑Sound level meters Part 1: Specifications, with
sound measuring equipment that complies with the requirements of
Schedule 4;
L A Slow max means the maximum reading in decibels
(dB) obtained using the “A” frequency weighting characteristic and
the “S” time weighting characteristic, as specified in
AS IEC 61672.1‑2004 Electroacoustics‑Sound level meters
Part 1: Specifications, with sound measuring equipment that complies with
the requirements of Schedule 4;
one‑third octave band means a band of
frequencies spanning one‑third of an octave and having a centre
frequency between 25 Hz and 20 000 Hz inclusive as incorporated in a
filter that complies with the requirements of Schedule 4.
(3) Noise is taken to
be free of the characteristics of tonality, impulsiveness and modulation
if —
(a) the
characteristics cannot be reasonably and practicably removed by techniques
other than attenuating the overall level of the noise emission; and
(b) the
noise emission complies with the standard prescribed under
regulation 7(1)(a) after the adjustments in the table to this
subregulation are made to the noise emission as measured at the point of
reception.
Table 2
[Regulation 9 amended: Gazette 5 Dec 2013
p. 5656‑7.]