Anechoic and Hemi-Anechoic Chambers: application context, design, and main benefits

The increasing demand for machinery and components with certified sound levels has led many companies to recognize the importance of having a controlled sound environment for conducting measurements. 

Nevertheless, traditional masonry rooms are not always cost-effective or flexible enough to meet these specific industrial requirements. 

Therefore, alternative solutions are being considered to better adapt to installation development and provide flexibility.

 

Typical applications of Anechoic and Hemi-anechoic Chambers

Anechoic chambers are targeted for various industries that require precise acoustic testing and analysis. Industries that commonly employ anechoic and hemi-anechoic chambers include:

  • Companies producing noise-generating devices or pieces of equipment. For instance, they are extensively used in the automotive sector for testing vehicle components, such as engines, exhaust systems, and vehicle interiors, to assess their noise levels, vibration characteristics, and acoustic performances. As a matter of fact, any vehicle manufacturer should perform a rigorous testing to ensure compliance with national planning standards before releasing a new model into a market.
  • Companies producing noise control products and testing facilities, as well as any organization responsible for ensuring that their services meet requirements, thereby establishing tightly regulated acoustic environments.

Designing Anechoic and Hemi-anechoic Chambers

Creating an insulated test environment is essential in the first place for precise noise analysis. 

Chambers can be either of an anechoic chamber or hemi-anechoic design pattern. What is the main difference?

  • Anechoic chambers are designed with sound-absorbent materials on all six sides, effectively eliminating external noise and controlling frequency cut-off. 
  • Hemi-anechoic chambers, on the other hand, have a solid floor with anechoic wedges on five sides, allowing examination of how noise interacts with real-world surfaces.

Anechoic and hemi-anechoic chambers are typically tailored to specific testing needs and frequency requirements, often aligned with ISO standards. 

The size of these chambers is primarily dictated by the equipment under test. Their sizes can range from extremely large ones used for instance in the case of automotive testing, to very small chambers, employed to test more compact devices.

 

Main benefits of Anechoic and Hemi-anechoic Chambers

As stated earlier, these chambers are instrumental to facilitate the development and testing of any noise-generating products

Another example of an industrial sector that has been significantly affected is the aerospace industry.  These chambers are particularly used in the fields of research and development to test aircraft engines, jet noise reduction technologies, aircraft interiors, and other aerospace components for noise emissions and acoustic characteristics.

In short, they give significant assistance in identifying unexpected noises and vibration issues that may arise during operations. For instance, many types of industrial machinery can be tested in a hemi-anechoic chamber to assess their vibration properties.

However, benefits are not just limited to sound isolation.

Anechoic and Hemi-anechoic chambers also provide total protection against electromagnetic interference, such as radio waves, which could disrupt the product or sensitive measuring instruments.

More importantly, unlike any other soundproofing chambers, which attenuate noise levels to around 10-20 dBA, Anechoic and Hemi-anechoic chambers can be designed to achieve even lower levels, reaching as little as -20 dBA if required.

 

Anechoic and Hemi-anechoic Chambers by Stopson Italiana

Stopson Italiana offers a range of prefabricated Anechoic or Hemi-anechoic Chambers that are internally treated with standard wedges, according to the lowest operating frequency. Our products are tailored for professional testing in various fields.

Our case history includes the implementation of a hemi-anechoic chamber for acoustic testing in a Home Appliances Plant, in Pordenone, Italy. The chamber in question was provided with a modular construction for easy dismantling and built with non-combustible sound absorbing materials.

Stopson Italiana’s anechoic chambers can also be optionally equipped with a control room. Such a setup provides working areas with sufficiently low sound pressure levels, limited reverberation, and ensures accurate acoustic performance.

Our anechoic chambers typically have a cut-off frequency of 125Hz and can be equipped with various features depending on their intended use. These features may include suitable interior lighting, exhaust gas extraction systems, independent ventilation and cooling systems, air-conditioned aspiration/exhaust, easy access to tested devices, safety glass for visual inspection during testing, and long-lasting soundproofing materials.

To Discover more Test Facilities Solutions offered by Stopson Italiana click HERE.