Workplace Noise Assessment — A Complete Guide for Health & Safety Professionals

A workplace noise assessment (also called a noise survey or noise risk assessment) is a systematic evaluation of noise levels in a workplace to identify where workers are exposed to levels that may damage their hearing, and to provide the basis for a hearing conservation programme. In most countries across Asia and the Middle East, employers are legally required to carry out a noise assessment when noise may exceed 80 dBA, and to repeat it whenever significant changes to noise sources or working patterns occur.

This guide explains the recommended assessment process and how SoundPLANmanda can significantly improve the quality, speed, and repeatability of workplace noise assessments.

Step-by-Step Noise Assessment Process

• Step 1: Facility walkthrough — Identify all significant noise sources (machines, processes, equipment) and note worker locations and typical task durations in each area
• Step 2: Noise level measurement — Use a calibrated sound level meter or noise dosemeter to measure noise levels in each area and for each task (ISO 9612 measurement strategies)
• Step 3: Build facility noise model — In SoundPLANmanda, create a 3D model of the facility with all noise sources, allowing noise to be mapped and predicted across the entire site
• Step 4: Generate noise maps — Run the model to produce color-coded noise maps at ear height, revealing the full spatial distribution of noise and identifying hotspots
• Step 5: Calculate worker exposure — For each worker or job role, calculate daily noise exposure (LEX,8h) based on time spent in each noise zone
• Step 6: Identify workers at risk — Flag all workers with LEX,8h above 80 dBA (lower action value) or 85 dBA (upper action value)
• Step 7: Evaluate and plan controls — Model engineering control options in SoundPLANmanda (enclosures, barriers, damping), evaluate HPE adequacy, and plan administrative measures
• Step 8: Document and report — Produce the noise risk assessment report, hearing protection zone map, and exposure records required by regulations

When to Repeat the Assessment

• After installing new machinery or modifying existing equipment
• After changes to production processes or working hours
• After implementing engineering controls (to verify effectiveness)
• As required by local regulations (typically every 2–5 years)

Common Mistakes in Workplace Noise Assessments

• Underestimating noise variation — Noise levels in manufacturing environments vary significantly with machine operation cycles, production volumes, and maintenance status. A single brief measurement may not represent typical conditions. ISO 9612 specifies minimum sampling requirements to account for this variability.
• Incorrect metric — Using Lmax instead of LAeq,T for exposure calculations leads to either over- or under-estimation of daily exposure. All time-weighted exposure calculations must use LAeq.
• Forgetting part-time workers and contractors — The assessment must cover all workers regularly present in the workplace, including cleaners, maintenance staff, and visiting contractors whose noise exposure may be significant.
• Not reassessing after changes — Installing new machinery, modifying processes, or changing shift patterns all require reassessment — not just updating records.

SoundPLANmanda automates and improves this process | ISO 9612 standard guide | Talk to our team