Advances in Hearing and Noise Control in the Workplace
By: Ryan D. Hill, CIH, CSP NV5, Contributor
Occupational noise-induced hearing loss (NIHL) remains a significant public health concern, affecting millions of workers globally. Prolonged exposure to high noise levels in the workplace not only endangers hearing but can also impair cognitive performance, increase stress and reduce overall productivity. Other than hearing loss, noise exposure has been linked to cardiovascular stress, sleep disturbances (for shift workers), decreased job satisfaction and accidents due to poor communication or inability to hear warnings.
To address this issue, regulatory bodies have established guidelines and standards to protect workers from excessive noise exposure. OSHA has set clear guidelines for noise exposure limits in the workplace. The permissible exposure limit (PEL) for an 8-hour workday is 90 decibels (dBA), measured using the A-weighted scale, which adjusts for the human ear’s sensitivity to different frequencies.
However, OSHA requires employers to implement a Hearing Conservation Program (HCP) when noise levels reach or exceed 85dBA over an 8-hour period, known as the action level (AL). Additionally, based on current scientific research, the American Conference of Governmental Industrial Hygienists (ACGIH) has developed a more stringent consensus standard called Threshold Limit Value (TLV) for occupational noise exposure. Adherence to these standards is recommended.
Utilization of the OSHA AL and the ACGIH TLV aims to protect workers before noise levels become hazardous. Understanding the impact of workplace noise is crucial for implementing effective control measures. Exposure to noise levels above 85dBA for prolonged periods is known to increase the risk of hearing damage.
While regulations and consensus standards are paramount to understanding noise exposures in the workplace, controls must be implemented when occupational noise levels are at hazardous levels. Controls can be implemented using three strategies: treating the receiver, treating the path/room and treating the source.
Advancements in Treating the Receiver

While PPE is essential, reducing noise before it hits the ear remains the most effective strategy at combating noise-induced hearing loss. © Oleksandr – stock.adobe.com
One development is the introduction of smart Hearing Protection Devices (HPDs). These innovative devices incorporate advanced technologies such as active noise cancellation (ANC) and real-time noise monitoring. By blocking harmful noise levels, while allowing communication through speech enhancement or selective filtering, smart HPDs offer dual benefits. Additionally, they provide data on cumulative noise exposure, enabling workers and employers to track and mitigate risks effectively.
The ANC capabilities in smart HPDs are powered by batteries, which require ongoing maintenance and may be difficult for supervision to decipher whether employees are in compliance with the company’s HCP. For this reason, employers should seek to achieve an adequate noise reduction rating (NRR) for exposure through passive attenuation, despite using these devices. In addition, noise-canceling headphones used for recreational purposes are not hearing protection and should never be allowed in an environment with high noise exposure. Employers should only allow ANSI-approved HPDs in the workplace.
Another technology, custom earplugs, while on the market for many years, have made some recent advancements to achieve an even better fit and effective NRR. 3D printing and digital scanning capabilities have created custom-fit earplug technology without expanding foam molds. These advancements offer better comfort and improved noise attenuation compared to traditional pre-molded foam or silicone options. This personalized approach ensures that workers receive optimal protection tailored to the individual.
The integration of HPDs with Internet of Things (IoT) systems represents another leap forward in workplace safety. By connecting these devices to workplace monitoring systems, employers can aggregate and analyze noise data for long-term planning and compliance. This seamless integration allows for more comprehensive and proactive noise management strategies.
While PPE is essential, reducing noise before it hits the ear remains the most effective strategy at combating NIHL. Recent innovations in engineering controls have led to significant improvements in noise reduction.
Advancements in Treating the Path/Room
Acoustic barriers and absorbers have also contributed to creating quieter workspaces. Advanced materials, such as micro-perforated panels (MPPs) and acoustic foam, are deployed to absorb noise effectively. These materials have shown remarkable results, especially in open-plan offices and manufacturing facilities where noise control can be particularly challenging.
All materials that a sound wave interacts with have a transmission coefficient or sound absorption coefficient (SAC). Different materials are effective at different frequencies and, thus, should be carefully chosen for the environment in which they will be installed. For instance, if the primary frequency of the facility is low, you will not want to install a polyurethane foam noise barrier, as they are more effective at high frequencies. On the other hand, MPPs can be designed for your specific noise profile and should be designed and installed by an acoustic engineering and installation team.

By investing in noise control measures and hearing protection technologies, employers can create safer, more productive work environments while reducing long-term healthcare costs associated with hearing loss. © Kings Access – stock.adobe.com
Advancements in Treating the Source
Engineers of modern machinery are now incorporating ANC systems into their designs. These systems are designed to actively cancel harmful frequencies using sound wave interference in real-time with a series of microphones and speakers set to generate a noise source at the opposite wave form of the noise in the environment. While this technology has typically been most effective at low-frequency noises, additional research is being conducted to determine designs that may be able to cancel the higher frequencies that are more damaging to the human ear. ANC is most effective when paired with acoustic barriers.
The “quiet design” concept has gained traction among manufacturers, encouraging them to prioritize noise reduction during product development. This approach ensures that equipment inherently produces less noise, addressing the issue at its source and reducing the need for additional noise control measures. With this in mind, owners of this equipment will still need to maintain it appropriately, as equipment that is not maintained often generates increasing noise levels.
Conclusion
Despite these advances, several challenges remain in implementing effective noise control measures. The cost of implementation can be a significant barrier, particularly for small and medium-sized companies that may find it challenging to invest in advanced technologies. Choosing the right technology may be difficult for those unfamiliar with their capabilities and limitations. It is recommended to seek the assistance of an industrial hygienist and/or an acoustic engineer to determine the best solutions.
Adopting new technologies also presents challenges, as integrating smart devices requires adequate training and infrastructure. However, the potential benefits of these advancements far outweigh the initial hurdles, if appropriately implemented. By investing in noise control measures and hearing protection technologies, employers can create safer, more productive work environments while reducing long-term healthcare costs associated with hearing loss.
Looking to the future, researchers are exploring innovative approaches to hearing protection and noise control. Inspired by the ear structures of animals known for acute hearing, biomedical hearing protection holds promise for developing more effective and comfortable protective devices. There is also ongoing research into the development of better adaptive ANC technologies.
Additionally, advancements in artificial intelligence are paving the way for predictive noise control systems that can adapt to changing environments in real time, offering unprecedented levels of protection.
Hearing protection and noise control are experiencing rapid advancements that could transform workplace safety. As industries adopt these innovations, a multidisciplinary approach involving technology, policy and education will be essential to ensure their effective implementation. With continued progress and commitment to worker safety, the vision of safer, quieter workplaces is becoming a reality, promising a future where occupational hearing loss is no longer a pervasive concern. IHW
References:
- Occupational Noise Exposure – Overview | OSHA.gov
- This source provides comprehensive guidelines on occupational noise exposure and its health implications. OSHA
- Noise and Occupational Hearing Loss | CDC
- The Centers for Disease Control and Prevention (CDC) offers detailed information on occupational hearing loss statistics and prevention strategies. CDC
- Occupational Hearing Loss Surveillance | Noise and Hearing Loss – CDC
- This resource discusses surveillance programs and data related to occupational hearing loss. CDC
- Occupational Noise Exposure: A Review of Its Effects, Epidemiology & Impact with Recommendations for Reducing Its Burden
- This academic article reviews the effects of occupational noise exposure and provides recommendations for mitigation. AIP Publishing
- How Smart Hearing Protection is Driving Reductions in Noise Exposure at Work
- This article explores the role of smart hearing protection devices in reducing workplace noise exposure. Britsafe
- Smart Earplugs & Technology-Driven Noise Reduction | Sensear
- Sensear discusses advancements in smart earplugs and their impact on noise reduction in industrial settings. Sensear
- Occupational Noise: Assessing the Burden of Disease from Work-Related Hearing Impairment
- The World Health Organization provides a method for estimating the disease burden of hearing loss caused by occupational noise. World Health Organization
- Occupational Noise-Induced Hearing Loss & Audiometry
- This rapid review discusses the effects of occupational noise-induced hearing loss and the role of audiometry in its assessment. SIRA
- Occupationally-Induced Hearing Loss | NIOSH | CDC
- The National Institute for Occupational Safety and Health (NIOSH) provides information on occupationally-induced hearing loss and preventive measures. CDC
- The Best Hearing Aids of 2024, Reviewed by Experts | WIRED
- This article reviews the latest advancements in hearing aid technology, relevant to workplace hearing protection. Wired
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