Noise exposure profiles W Williams National Acoustic Laboratories Annual Conference NHCA February 25 th – 27 th, 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 L Aeq,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 L Aeq,8h of 85 dB is one allowable daily exposure (ade) – approximately 1 Pa 2 h. An allowable yearly exposure (aye) is equivalent to 220 aye (based on the assumption that there are 220 working days per year).

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 L Aeq → 105 dB for 5 hrs ≡ 9.5 Pa 2 h* Dance parties and concerts L Aeq → 110 dB for 4 hrs ≡ 160 Pa 2 h* *E A,T = 4 x T (LAeq – 100)

Age (yrs) Music (events/yr) Music (aye/yr)) (0.043/event) Table 1: Age and attendance at music events

Noise exposure of an individual exposed to music only showing rate and 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)

Age (yrs) Dance/ concerts (aye/ year) Concert (aye/yr) (0.732/event) 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

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

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

Conclusion Noise exposure profiles are a convenient way of looking at sources of significant noise exposure