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Noise exposure profiles
W Williams
National Acoustic Laboratories
Annual Conference NHCAFebruary 25th – 27th, 2010
Orlando , FL
What is a‘noise exposure profile’
A noise exposure profile is a method of
illustrating the cumulative noise exposure of
an individual over a period of time.
This can be for any time period such as an
LAeq,8h for one day or for a complete life-time.
Why would I/we want a noise exposure profile?
They can be used to visualise and/or
demonstrate the relevant importance of
different sources of noise exposure over an
extended time period.
Definitions
• An LAeq,8h of 85 dB is one allowable daily exposure (ade) – approximately 1 Pa2h.
• An allowable yearly exposure (aye) is equivalent to 220 aye (based on the assumption that there are 220 working days per year).
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
0 10 20 30 40 50 60 70
Age (years)
Exp
osu
re (a
ye)
exposure rate
cumulative exposure
Noise exposure of an individual exposed at a rate of one aye/year over a working life of 42 years (18 to 60) showing rate of exposure and cumulative exposure
Now consider the influence of a couple of leisure activities:-
• Pub/ Dance/Night Club music events
LAeq → 105 dB for 5 hrs ≡ 9.5 Pa2h*
• Dance parties and concerts
LAeq → 110 dB for 4 hrs ≡ 160 Pa2h*
*EA,T = 4 x T 10 0.1(LAeq – 100)
Age(yrs)
Music(events/yr)
Music (aye/yr))
(0.043/event)
17 4 0.17
18 12 0.52
19 14 0.60
20 15 0.65
21 15 0.65
22 12 0.52
23 10 0.43
24 8 0.34
Table 1: Age and attendance at music events
Noise exposure of an individual exposed to music only showing rate and cumulative exposure
0
1
2
3
4
5
15 20 25 30
Age (years)
Ex
po
su
re (
ay
e)
Exposure per year
Cumulative exposure
Cumulative noise exposure of an individual exposed at a rate of one aye/year over a working life of 42 years (18 to 60) and music for eight years (17 to 24)
0
2
4
6
8
10
12
14
16
18
20
15 20 25 30 35
Age (years)
Ex
po
su
re (
ay
e)
Work
Music
Work + Music
Age(yrs)
Dance/concerts
(aye/ year)
Concert (aye/yr)
(0.732/event)
17 - -
18 2 1.46
19 4 2.92
20 4 2.92
21 4 2.92
22 4 2.92
23 4 2.92
24 - -
Table 2: Age and attendance at dance parties and concerts
Noise exposure of an individual exposed to concert music showing rate of exposure and cumulative exposure
0
2
4
6
8
10
12
14
16
18
15 16 17 18 19 20 21 22 23 24 25
Age (years)
Exp
osu
re (
aye)
Cumulative concert exposure
Concert exposure rate
Now combine work, music and concert
exposure
Cumulative noise exposure of an individual exposed at a rate of one aye/year over a working life of 42 years, music for eight years and concert music for six years
0
10
20
30
40
50
60
70
15 25 35 45 55 65
Age (years)
Exp
osu
re (
aye)
Work
Music
Concerts
Work+Music+Concerts
By retirement at age 60
• Work only has 42 aye
• Work + music + concerts has 62 aye
- which the combined music/concert goer
reached at ~ 40 years
Cumulative noise exposure of an individual exposed at a rate of one aye/year over a working life of 42 years, music for eight years and concert music for six years
0
10
20
30
40
50
60
70
15 25 35 45 55 65
Age (years)
Exp
osu
re (
aye)
Work
Music
Concerts
Work+Music+Concerts
Conclusion
Noise exposure profiles are a convenient
way of looking at sources of significant noise
exposure
