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Peak Level
The peak level is the crest of the signal or sound pressure wave. The figure
below shows the peak level and its corresponding rms level: -
-1
0
1
Time
Peak levels are commonly measured incorporating the C-weighted and Z-
weighted frequency weighting filters and can be much higher than the rms
sound pressure level.
See the indicative image below which shows a peak level of 123dB but the rms
value is only 66dB.
0
20
40
60
80
100
120
140
0
1
2
3
4
5
6
7
8
9
10
11
12
dB
time
Lp
rms
See also ‘Root Mean Square (rms)’ and ‘Action Values’.
Pink Noise
This is a random signal where each octave contains equal energy. Low
frequencies will be more dominant with pink noise due to its power spectrum
decay of a constant -3dB per octave as the frequency increases.
peak
rms
