Pollution Control Consultancy and Design

Acoustical Consultants (Noise and Vibration) - Sydney

Sound Power

With our comprehensive academic qualifications coupled with extensive practical engineering experience and technical skills, and with our all-inclusive, world-class, specialist measuring equipment and software, we will find effective solutions to essentially any noise problems.

Sound Power Level is a measure of the sound energy emitted from a source of noise.

The advantage of using the sound power level, rather than the sound pressure level, in reporting equipment noise is that the sound power is an inherent property of the equipment - it does not depend on the:

  •  location of the equipment;
  •  environmental conditions; and
  •  distance from the measurement point.


The sound power level (and not the sound pressure level) should be an essential part of modern technical specifications of any equipment that may cause environmental and/or occupational noise problems.


Traditionally, the sound power level has been determined by measurements of the sound pressure level of a piece of equipment that needs to be placed during these measurements:

  • inside the anechoic or reverberant chambers (very expensive); or
  • in the acoustically free-field (in many cases unattainable).

Today , using state-of-the-art sound intensity technology, sound power level of your product or equipment that you use may be determined in-situ, in your laboratory or factory, without any special arrangements.

Sound power and sound intensity 

During sound intensity measurements your equipment may operate at any location.


Furthermore, sound intensity measurements eliminate steady extraneous background noise, which means that you do not need to stop other, nearby equipment during the measurements.

Sound power The measurements of sound intensity are carried out over a close, imaginary box (of any shape, e. g. a cuboid or rectangular parallelepiped, as in the diagram on the left) surrounding a piece of equipment operating in situ.  Based on these measurements, the sound power level of the piece of equipment is determined by the sophisticated analyzer.


We carry out sound intensity measurements with Brüel & Kjær (B&K) Modular Precision Real-Time Sound Analyzers type 2270, with Sound Intensity Probe type: 3595 with a Pair of Microphones type:  4197 (state-of-the-art hand-held sound intensity system).

Using this system, the sound power level may be determined according to:

ISO 9614-1 : 1993
      Acoustics - Determination of sound power levels of noise sources using sound intensity Part 1:  Measurement at discrete points.
International Organization for Standardization
ISO 9614-2 : 1996
     Acoustics - Determination of sound power levels of noise sources using sound intensity Part 2:  Measurement by scanning.
International Organization for Standardization
ANSI S12.12 - 1992 (R2017)
     Engineering Method For The Determination Of Sound Power Levels Of Noise Sources Using Sound Intensity
Acoustical Society of America
ECMA 160 Ed. 2 (1992)
     Determination Of Sound Power Levels Of Computer And Business Equipment Using Sound Intensity Measurements; Scanning Method In Controlled Rooms.
European Computer Manufacturers Association