Technical Column
Setting Background Noise Levels in an Anechoic Chamber
May 27, 2025
- HBK × SONORA Acoustic Measurement Solution Official Website
- Technical Column
- Setting Background Noise Levels in an Anechoic Chamber
Acoustic Power Measurement
How to Set Background Noise Levels in an Anechoic Chamber
Background noise refers to the ambient sound present when the test source is inactive—in other words, the baseline quietness of the anechoic chamber.
While this may sound straightforward, there are several important considerations when defining acceptable background noise levels.
Recommended Background Noise Thresholds
The background noise level must be significantly lower than the acoustic power level of the device under test (DUT).
A common guideline is that the background noise should be at least 10 dB lower than the minimum sound pressure level to be measured.
To enable the measurement of quieter sources, the chamber’s background noise must be proportionally lower.
Designing for Environmental Noise and Vibration
To achieve a sufficiently low background noise level, the chamber must be designed with proper sound insulation and vibration isolation, tailored to its installation environment.
Let:
- A = Environmental noise and vibration level at the installation site
- B = Sound insulation and vibration isolation performance of the chamber
- C = Background noise level inside the anechoic chamber
Then:
A – B = C
In other words, the target background noise level (C) is determined by the measurement requirements.
From this, the required chamber performance (B) can be calculated based on the site conditions (A).
If the installation site is subject to high levels of ambient noise or vibration, higher-performance insulation and isolation measures will be required to meet background noise targets.
Latest Posts in Technical Column
-
2025.12.06
Integrated Design of Anechoic Chambers with Auxiliary Equipment — Balancing Silence and Functionality — -
2025.11.30
Modular Semi-Anechoic Chambers — A Flexible Solution for Deployable Acoustic Testing — -
2025.11.25
Measuring Silence: How Anechoic Chambers Support Industrial Quality -
2025.11.18
Designing for Reproducibility — Environmental Stabilization in Acoustic Measurement — -
2025.11.13
The New Generation of Mobile Acoustic Measurement — Field Accuracy for Building and Environmental Sound Testing — -
2025.11.07
The Design Logic Behind the Inverse Square Law Zone in Anechoic Chambers -
2025.10.31
Acoustic Cameras and Anechoic Chambers — Visualizing Silence for Sound Source Analysis — -
2025.10.25
Integrated Acoustic and Vibration Analysis — Designing the Data Flow That Connects Measurement and Insight— -
2025.10.20
End-of-Line Acoustic Testing — Quantifying Quietness in Mass Production — -
2025.10.14
Designing the Future of Silence — The Fusion of Digital Acoustic Measurement and Spatial Engineering —
Contact Us
- Contact us by email
-
- Contact us by phone
-
Moritani Shokai
(Machinery Department No. 2, Tokyo Head Office)
Introduction of the Manufacturer
-
Hottinger Bruel & Kjaer
HHBK is a merger of two companies: Brüel & Kjær of Denmark and HBM of Germany.
Brüel & Kjær is one of the world’s leading manufacturers of acoustic and vibration measurement instruments, known as a total measurement chain supplier.Learn more about HBK
-
Sonora Technology Co., Ltd.
Sonora Technology is a leading Japanese manufacturer of industrial anechoic chambers and anechoic boxes.
From design and manufacturing to installation and acoustic performance assurance, Sonora provides fully integrated solutions to build complete acoustic measurement environments from the ground up.Learn more about Sonora
Contact / Request Brochure
For inquiries or consultations regarding the total solutions provided by HBK × Sonora, please feel free to contact us using the Contact button.
If you would like a brochure sent by mail, please use the Request Brochure button.