Noise exposure · GB · 8-hour reference
Calculate daily noise exposure from multiple tasks
Combine task noise readings into an eight-hour energy-normalised daily exposure.
By HSECalc · Published
Check that this method fits your task
GB daily noise exposure calculation from representative task levels and durations. It does not assess peak sound pressure, weekly alternatives or hearing-protector performance.
Choose your inputs and work through the steps
- List the workday’s noise tasks with representative dB(A) levels and exposure durations. Do not use peak dB(C) readings as task levels.
- Enter hours and minutes for each non-overlapping task. Cover the exposure inventory rather than treating unknown work as quiet.
- Combine the energy contributions using the calculator. Retain actual time and level records so the daily result can be reproduced.
L_EP,d = 10 log10[Σ((task hours ÷ 8) × 10^(task dB(A) ÷ 10))]. Decibel readings are combined by energy, not arithmetic averaging.
A worked example
Illustrative values explain the tool; they are not prescribed inputs for your work.
- Fictional tasks: 85 dB(A) for 4 h and 88 dB(A) for 4 h.
- Relative to 85 dB(A), energy sum = 4/8 + (4/8)×10^(3/10) = 1.4976.
- Daily exposure = 85 + 10log10(1.4976) = 86.75 dB(A), about 150 points: above the upper action value.
Read the result and decide what needs checking
GB daily/weekly lower and upper exposure action values are 80 and 85 dB(A). Action values do not account for hearing protection; the 87 dB(A) exposure limit does account for it. This tool’s unprotected daily result cannot by itself establish limit compliance.
Use the HSE guidance to assess controls and hearing-protection arrangements. Peak exposure has separate values and is outside this tool. A lower daily value does not rule out a peak-noise problem.
Common questions
Can I average 80 and 90 dB(A) directly?
No. The energy contribution and exposure duration determine the combined value.
Does entering hearing-protection attenuation reduce this result?
No. This tool does not assess protection. Action-value assessment uses exposure without accounting for hearing protection.
Does the calculator check impulsive noise?
No. Peak sound pressure needs separate measurement and assessment.
References and scope notes
- HSE noise exposure calculators
- HSE noise regulations and exposure values
- Control of Noise at Work Regulations, Schedule 1
Use the current official guidance and the instructions for your actual equipment. HSECalc is independent; a reference is not an endorsement. Read how we use methods and sources or report a correction.