Enter the equivalent continuous sound level (typically dB(A)) and the exposure time to estimate the HSE 8-hour daily noise exposure level (LEX,8). This calculator estimates LEX,8 from common inputs and can help you understand how sound level and time affect daily exposure.

HSE Noise Exposure Calculator

Enter any 2 values to calculate the missing value (8-hour reference)

This calculator assumes A-weighted levels (dB(A)) consistent with common HSE LEX,8 reporting.

Disclaimer: For informational use only. This tool does not replace a professional occupational noise assessment or workplace compliance evaluation. If you have concerns about hearing, symptoms, or workplace compliance, consult a qualified professional and follow official guidance (for example, UK HSE “Control of Noise at Work” guidance, or OSHA/NIOSH guidance in the US).

Interpretation & Next Steps

LEX,8 is often compared to regulatory “action” and “limit” values. Requirements differ by country and workplace policy—always check your local regulations and official guidance.

  • Common UK HSE daily exposure benchmarks (A-weighted): lower exposure action value 80 dB(A), upper exposure action value 85 dB(A), and exposure limit value 87 dB(A) (often defined as taking hearing protection into account).
  • Peak/impulsive noise: requires separate assessment (commonly using C-weighted peak values, dB(C)). A daily LEX,8 result alone may not capture peak risk.
  • If your results are high: consider engineering controls, administrative controls (reducing time), hearing protection, and a formal workplace noise survey by a competent professional.

Related Calculators

HSE Noise Exposure Formula

The following formula is used to estimate the 8-hour daily noise exposure level (LEX,8) from an equivalent continuous sound level measured over time T:

L_{EX,8} = L_{Aeq,T} + 10 \cdot \log_{10}\!\left(\frac{T}{8}\right)

Variables:

  • LEX,8 is the daily noise exposure level normalized to 8 hours (typically reported in dB(A))
  • LAeq,T is the equivalent continuous sound level over the exposure period T (typically in dB(A))
  • T is the exposure time (hours)

To calculate LEX,8, add the sound level to 10 times the base-10 logarithm of the time ratio T/8. (Because the logarithm requires a dimensionless quantity, T is compared to the 8-hour reference duration.)

What is Noise Exposure?

Noise exposure is a way to describe how much sound energy an individual is exposed to over a period of time, taking into account both the sound level and the duration of the exposure. In occupational settings, HSE commonly uses an 8-hour normalized daily exposure level (LEX,8) to help assess the risk of hearing damage or loss and to guide control measures.

How to Calculate Noise Exposure?

The following steps outline how to calculate the daily noise exposure level:

  1. Determine the equivalent continuous sound level (LAeq,T) in decibels (typically dB(A)).
  2. Determine the exposure time (T) in hours.
  3. Use the formula from above: LEX,8 = LAeq,T + 10 · log10(T/8).
  4. Calculate the daily noise exposure level (LEX,8) in decibels.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Sound Level (LAeq,T) = 85 dB(A)

Exposure Time (T) = 8 hours (so LEX,8 = 85 + 10·log10(8/8) = 85 dB(A))