Sound level meters measure area noise while personal dosimeters measure individual cumulative exposure

Two instruments characterise occupational noise. A sound level meter (SLM) measures noise at a given point and time, useful for mapping which areas or equipment are loudest and estimating exposure where levels are fairly constant. A personal dosimeter is worn by the worker and averages noise over the full shift, computing a noise dose. When noise levels vary (as in a live sound environment), dosimeters give the most accurate individual exposure assessment. NIOSH recommends the same core settings for both: 3-dB exchange rate, A-weighting, and slow response.

Examples

Use an SLM to locate the loudest monitor speaker position on stage. Attach a dosimeter to a FOH engineer for the full event to measure their actual personal exposure across a variable-level set.

Assessment

Explain why an SLM reading of 88 dBA taken at the FOH position might underestimate a sound engineer’s actual dose, and identify which instrument would give the correct measurement.