Technical Column

What Is Background Noise?

2025年5月26日

Acoustic Power Measurement

Background noise refers to the ambient sounds or noise that are present in the environment in addition to the sound being measured.
This includes constant sounds such as those coming from outside a room, mechanical equipment, or people talking nearby.
Background noise can affect both measurements and acoustic design, so accurately understanding and controlling it is essential.

Example of Background Noise

When measuring the sound pressure level of a ventilation fan inside an anechoic chamber,
the sound level in the chamber without the fan operating (or when there is no fan installed) is considered the background noise.

It is recommended that background noise be at least 10 dB lower than the sound level of the object under test.

For example, if the ventilation fan emits 50 dB, then the background noise level inside the anechoic chamber should be designed to be 40 dB or lower.

Background noise is the sound or noise present behind the target sound being measured, and it is crucial to properly manage its influence during acoustic measurement and evaluation.

お問い合わせ

Contact Us

Contact us by email







    Contact us by phone

    Moritani Shokai
    (Machinery Department No. 2, Tokyo Head Office)

    +81-3-3278-6127

    • Download

      Download

      You can download our brochure (PDF) from here.

    • Faq

      Faq

      Here you can find answers to common questions about the HBK × Sonora solutions.

    Introduction of the Manufacturer

    • ホッティンガーブリュエルケアー 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

    • ソノーラテクノロジー 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.