Acoustics
Sorry, the interactive calculator works only with browsers that support Javascript. But you can get an idea of how noise exposure adds up as follows:
An exposure of 80 dB (the lower action Level of the Noise at Work regulations) can be reached by a continuous exposure to the following noise level and duration, during one working day:
Level 
Duration 

80 dB  8 hours  
83 dB  4 hours  
86 dB  2 hours  
89 dB  1 hour  
92 dB  30 minutes  
95 dB  15 minutes  
98 dB  8 minutes  
101 dB  4 minutes  
104 dB  2 minutes 
Doubling the duration of exposure to a constant noise has the same effect on the exposure as increasing the level by 3 dB.
Relatively short breaks have little effect. In an 8
hour shift, the reduction in exposure given by a quiet break is as
follows:
Break in 8 hr shift  dB reduction  
30 minutes  0.3 dB  
50 minutes  0.5 dB  
1 hr 40 min  1.0 dB  
2 hr 20 min  1.5 dB  
3 hours  2.0 dB 
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