Protecting Workers from Hidden Noise Exposure Risks: Why 85dB TWA Isn't Enough

Noise pollution is a growing and often overlooked health hazard. Globally, over 1.5 billion people experience hearing loss today, with projections estimating this number will rise to 2.5 billion by 2050 (WHO, World Report on Hearing). While environmental noise from traffic, urban development, and personal audio devices contributes significantly, workplace noise exposure remains one of the most immediate and controllable risks.

Robert Koch, the Nobel Prize-winning scientist, once predicted, "One day man will have to fight noise as fiercely as cholera and pest." That day is now. Chronic exposure to loud environments is not just an inconvenience—it has real and lasting consequences on health, including cardiovascular disease, cognitive decline, and heightened stress levels. A study published in Environmental Health Perspectives found that over 100 million Americans were exposed to a 24-hour average noise level of 70 dB or higher, levels known to increase stress hormones and inflammation.

The Hidden Risks of Occupational Noise Exposure

For workers in manufacturing, construction, and industrial environments, daily noise exposure often exceeds safe thresholds. OSHA sets the permissible exposure limit at 90 dB for an 8-hour shift, but the recommended action level starts at 85 dB TWA (time-weighted average). Employees working at this level are effectively taking in 100% of their daily allowable noise dose. The problem? That dose assumes zero additional noise exposure outside of work.

In reality, workers leave their shifts and continue encountering loud environments—concerts, sports events, home power tools, and even everyday city noise. Unlike other workplace hazards, noise exposure doesn’t end when the workday does. This accumulated exposure significantly increases the risk of permanent hearing loss, tinnitus, and other health complications. A recent report by the European Environment Agency highlights that at least one in five Europeans is exposed to harmful long-term noise from road, rail, and air transport, with significant public health consequences, including sleep disturbances and an increased risk of cardiovascular disease.

The Role of Hearing Conservation in Preventing Long-Term Harm

At Soundtrace, we see this reality play out every day. Many employees in hearing conservation programs are already at their noise limit before they even step out of the workplace. Without proactive measures, their hearing and overall health remain at risk.

Our approach goes beyond compliance. We provide companies with the tools to assess noise exposure accurately, conduct in-house audiometric testing, and ensure workers have properly fitted hearing protection. But beyond that, we advocate for education—helping workers understand that their hearing health doesn’t reset at the end of their shift.

The Need for a New Approach

The data on noise pollution is clear: exposure thresholds should not be treated as a hard stop, but rather a warning signal. If an employee is reaching 100% of their allowable noise dose at work, employers must take additional steps to mitigate risk. This includes fit testing for hearing protection, implementing noise monitoring programs, and fostering a culture where employees are mindful of their total noise exposure—both on and off the job.

We must stop viewing noise exposure as an isolated workplace issue and instead recognize it as a 24-hour cumulative risk. Companies that take this approach will not only improve employee well-being but also reduce the long-term costs associated with hearing loss-related claims and productivity loss.

Hearing loss is preventable—but only if we start treating it with the urgency it deserves.

If you’re interested in learning more about how Soundtrace is helping companies build better hearing conservation programs, reach out to us today.