Noise Monitoring in Manufacturing

CNC lathes, milling machines, and metal cutting saws generate high-frequency noise from tool-workpiece contact and broadband noise from spindle motors and coolant pumps. Operators stationed at machines for the full shift accumulate noise doses that commonly exceed the WES. Enclosures and acoustic barriers require verification through post-installation noise monitoring.

Stamping presses, punch presses, and forming presses generate impulsive noise at levels that can exceed 110 dB(A) per stroke. Press operators and nearby workers are exposed to both continuous background noise and impulse peaks. Assessment must include LC,peak measurement to confirm compliance with the 140 dB(C) peak limit.

Bench grinders, pedestal grinders, belt sanders, and angle grinders used in metal finishing generate sustained high-frequency noise at 95-105 dB(A) at the operator position. The intermittent nature of grinding tasks makes personal dosimetry the most reliable assessment method.

Air compressors, pneumatic tools, and compressed air blow-off nozzles generate broadband noise. Open blow-off nozzles are one of the most common sources of unnecessary noise in manufacturing and can be readily controlled with engineered nozzle replacements. Compressor rooms require acoustic treatment to prevent noise transmission to adjacent work areas.

Typical Worker Groups

Common similar exposure groups (SEGs) assessed for this sub-category.

Regulatory Context

The WHS Regulation requires PCBUs to ensure worker noise exposure does not exceed the WES of 85 dB(A) LAeq,8h or 140 dB(C) peak. Where noise levels exceed these limits, a hierarchy of controls must be applied with engineering controls prioritised over administrative controls and HPDs. Audiometric testing (hearing tests) must be provided to workers with significant noise exposure within three months of commencing work and at intervals not exceeding two years. The Managing Noise and Preventing Hearing Loss at Work Code of Practice provides detailed guidance on assessment methodology, control selection, and hearing conservation programme requirements.