Which noise level corresponds to a daily exposure time of two hours?

Which noise level corresponds to a daily exposure time of two hours?

• A. 100 dB
• B. 90 dB
• C. 110 dB
• D. 115 dB

Answer: (A)

The key idea is how noise level and daily exposure time relate under the 5 dB exchange rate used in many workplace noise standards. With this rate, for every increase of 5 dB, the permissible exposure time halves. If 90 dB is allowed for 8 hours, then: - 95 dB allows 4 hours - 100 dB allows 2 hours - 105 dB allows 1 hour - 110 dB allows 30 minutes - 115 dB allows 15 minutes So a daily exposure time of two hours corresponds to a noise level of 100 dB. The other options correspond to longer or shorter exposure times (90 dB for 8 hours, 110 dB for 30 minutes, 115 dB for 15 minutes), not two hours.

The key idea is how noise level and daily exposure time relate under the 5 dB exchange rate used in many workplace noise standards. With this rate, for every increase of 5 dB, the permissible exposure time halves. If 90 dB is allowed for 8 hours, then:

• 95 dB allows 4 hours

• 100 dB allows 2 hours

• 105 dB allows 1 hour

• 110 dB allows 30 minutes

• 115 dB allows 15 minutes

So a daily exposure time of two hours corresponds to a noise level of 100 dB. The other options correspond to longer or shorter exposure times (90 dB for 8 hours, 110 dB for 30 minutes, 115 dB for 15 minutes), not two hours.