
Noise Control in Industrial Workplaces
Understanding Industrial Noise Exposure
Industrial noise remains one of the most common occupational health hazards. OSHA sets the permissible exposure limit at 90 dBA for an 8-hour time-weighted average, with a 5 dB exchange rate. Workers exposed above 85 dBA must be enrolled in hearing conservation programs.
Hierarchy of Noise Control
Source Control
The most effective approach targets noise at its origin. Replace worn bearings, install vibration isolators on machinery, and use low-noise equipment specifications during procurement. Enclosing noisy components in acoustic housings can reduce emissions by 10-20 dB.
Path Control
Interrupt noise transmission between source and receiver. Acoustic barriers, absorptive ceiling panels, and wall treatments all contribute. For airborne noise, mass-loaded vinyl barriers provide 25-30 dB insertion loss. For structure-borne vibration, spring isolators or resilient mounts decouple machinery from building elements.
Absorption Materials Selection
- Mineral wool panels (50-100mm): Broad-band absorption, NRC 0.85-1.05
- Perforated metal absorbers: Tuned to specific problem frequencies
- Microperforated panels: Clean-room compatible, fiber-free solution
- Suspended baffles: Effective in high-ceiling industrial spaces
Administrative Controls
When engineering solutions are insufficient, rotate workers to limit individual exposure duration. Schedule noisy operations during shifts with fewer personnel. Establish quiet zones where workers can rest away from noise.
Measurement and Monitoring
Conduct baseline noise surveys using Type 1 sound level meters with octave band analysis. Install permanent noise monitoring stations in high-risk areas. Review dosimetry data quarterly to track program effectiveness and identify emerging problem areas.
Designing an Effective Program
A comprehensive noise control program combines engineering controls, administrative measures, and personal protective equipment. Document all interventions with before-and-after measurements. Annual audiometric testing tracks worker hearing thresholds and validates your program's effectiveness.









