- These Are Two Of A Whole Series Of Levels Collectively Known As The Ln Values Can Be Any Number From 0 1 To 99 9 Assu 1 (1.89 MiB) Viewed 64 times
Max(dB-A)
Ave (dB-A)
Min(dB-A)
Peak (dB-A)
9AM
80.40
43.00
24.70
87.40
3PM
65.50
39.00
26.50
71.70
9PM
63.50
35.60
24.50
68.80
values
- These are two of a whole series of levels collectively known as the Ln values. can be any number from 0.1 to 99.9 assuming the system has a 0.1dB resoluti There is no international standard to describe these, despite them being vi widely used in environmental noise work. They are usually defined as:- the leve in decibels exceeded for n% of the time. The critical word is “exceeded' and tl has caught out many workers who failed to see the maths behind the word. [3] L10 Noise level in decibel exceeded for 10% of the time, also known Annoyance level; L90 Noise level in decibel exceeded for 90% of the time, also known : Background level; Lso Noise level in decibel exceeded for 50% of the time, also known a Standard level; Leq - Equivalent Continuous Sound Level: Leg = 1019 (L"100.114 dt] (1) Where LA is instantaneous sound pressure level in dB(A), and T is the period of measurement. When sample rate is a constant, Leq can be also presented as: (2) Where Lai is ith sound pressure level in dB(A), and n is the number of samples. Leq = 1019 [22-, 100.111] -