Current & Emerging Technological Advances in Noise Control

Advancements in noise control technology are equipping employers with more efficient and versatile solutions for managing noisy environments. © somchai20162516 – stock.adobe.com

By: Courtney Hansen, Contributor

Managing noise exposure is a critical challenge for employers, particularly in industrial environments. Noise can be generated from a wide range of sources, including vehicles, electrical equipment, air handling equipment, power tools and manufacturing machinery. Excessive noise levels can lead to hearing loss, elevated stress and reduced employee productively—resulting in both direct and indirect costs to employers.

While many employers rely on PPE, such as ear plugs or earmuffs, the hierarchy of controls dictates that PPE should be the last line of defense. Engineering controls are the preferred method of hazard mitigation. Continuous development of noise control technology offers innovative solutions to address noise impacts, ranging from soundproofing to noise cancelling. This article explores the technology behind these solutions, current market status and practical applications.

Established in Market—Active Noise Control

Active noise control (ANC) is a widely recognized technology in the audio markets, particularly for noise-canceling headphones. The ANC utilizes a sensor or microphone to detect incoming sound waves and then emit counteracting sound waves to cancel or reduce the noise. This method is especially effective with low-frequency sound waves common in urban environments, like roadway noise, equipment hum and office chatter1.

In recent years, this technology has been applied to larger scale industrial and urban applications. Companies often integrate ANC into panels that can be installed in noise-affected areas to mitigate noise impact2. For example, multiple panels can be installed at a substation near a residential neighborhood. When activated, these panels generate counteracting sound waves to reduce noise impact from the substation on nearby residential homes. Similarly, another company integrates intelligent ANC into products such as car headrests to create a “quiet zone” around the individual’s head3. This technology uses sensors on the wheels to monitor road surface vibrations and calculate, in real-time, the sound waves needed to reduce noise impacts from road conditions4.

Emerging In Market—Nanotechnology in Acoustic Insulation

For decades, acoustic insulation has been utilized to dappen noise in homes, offices, movie theaters, recording studios and other environments. Recent advancements in nanotechnology have increased the effectiveness of acoustic insulation, in some cases doubling noise efficiency compared to standard acoustic insulation5. This improvement is achieved by increasing the sound-absorbing surface area of the material through the injection of nanoparticles or the use of nanofibers, which disrupts the sound wave propagation.

This technology has been brought to market by a company called NanoLayr, through a product called SonoLayr6. This thin, sound-absorbing media uses layers of nanomaterials to substantially increase the sound-absorbing surface area while maintaining a lightweight profile. This type of material can be added to office cube separators, wall construction and even the interior of vehicles to reduce noise levels from external sources.

As noise control technologies continue to develop and become more accessible, they can provide employers powerful tools for creating quieter, safer and more productive work environments.

Active Development—Acoustic Metamaterial Rings

Acoustic metamaterial rings are a developing technology particularly useful in office environments for reducing noise from air handling units and fans. In 2019, researchers at Boston University made significant breakthroughs in this field, developing a design capable of blocking 94% of sound while allowing air to pass through the sound blocking device7. The researchers, Xin Zhang and Reza Ghaffarivardavagh, innovated a ring-like structure designed with mathematical precision to intercept sound waves, thereby reducing their overall impact and the effective noise received.

Since 2019, researchers have continued to build upon the foundation laid by Zhang and Ghaffarivardavagh. As recently as July 2024, researchers in Glasgow published a study on the fabrication of acoustic metamaterials for low-frequency sound control, particularly in the sub-100 Hz regime8. This innovation addressed fabrication limitations in this regime by developing an acoustic metamaterial cell with adjustable resonance. As these technologies continue to develop, they hold promise for reducing the noise impacts from sources such as compressors, turbines, boilers and engines.

Advancements in noise control technology are equipping employers with more efficient and versatile solutions for managing noisy environments. As these technologies continue to develop and become more accessible, they provide employers powerful tools for creating quieter, safer and more productive work environments. By implementing these advanced noise control solutions, employers can reduce reliance on PPE and engineer out the workplace noise hazards. The ongoing development of noise control technology promises even more effective and adaptable solutions, furthering employers’ ability to manage noise in industrial settings. IHW

About the Author:

Courtney Hansen works at NV5 as Environment, Health, & Safety (EHS) Associate III. She can be reached at Courtney.Hansen@NV5.com.