Acoustics

For road traffic noise monitoring, a microphone is positioned at a given point next to a highway or major road, and a sound level meter is used to record level fluctuations as well as actual sound at the site. With a constant monitoring system, interval measurement is also possible. Noise events are detected automatically and evaluated to determined whether they are aircraft noise.

Use a general-purpose sound level meter or high-precision sound level meter. Set frequency weighting to “A”, and set time weighting to “F” (Fast) or “S” (Slow), as appropriate for the type of sound to be measured. Then measure sound level.

Use the general-purpose sound level meter NL-42 or high-precision sound level meter NL-52 for monitoring environmental noise.

For aircraft noise monitoring, a microphone is positioned in the vicinity of the airport or at a point in the flight path, and a sound level meter is used to record level fluctuations as well as actual sound at the site. In a constant monitoring system, noise events are detected automatically from level fluctuations and are evaluated to determine whether they are aircraft noise. A system for detecting ground-level sound events occurring at airports can also be configured.

Use a sound level meter to monitor factory sounds at the boundary of the site.

Use a sound level meter to monitor noise from construction activities

This system uses an SA-02 and dedicated software to realize acoustic power level measurements either with the semi-anechoic or the reverberant method. Even if the generated noise energy is the same, machinery, electrical products, office equipment and similar will produce different ambient sound levels, due to a number of factors. When installing or removing equipment, measurement of acoustic power levels, i.e. acoustic energy produced per time unit, is necessary for predicting noise levels. The same applies when evaluating equipment on its own, with regard to its behavior as a sound source. To measure the acoustic power level of a sound source, a measurement system consisting of measurement microphones and preamplifiers, a multi-channel signal analyzer SA-02 series unit, and acoustic power level measurement software is used.

This system reads measurement data files recorded by the SA-02 and calculates sound quality and acoustic evaluation quantities (loudness, sharpness, roughness, etc.). By using the same hardware (SA-02 etc.) and only changing the software, various evaluation quantities can be calculated.

Visualization of a particular sound is possible by using an acoustic intensity measurement system or sound source location system.
Visualization of a particular sound is possible by using an acoustic intensity measurement system or sound source location system.
The acoustic intensity measurement system uses multiple measurement points arranged in a mesh pattern to accurately measure sonic intensity. When measurement for all measurement points has been completed, a contour diagram or similar is drawn to visualize the result. However, the contour diagram can only be created after measurement has been completed.
The sound source localization system on the other hand graphically shows the arrival direction of sound in real time. This allows making a judgment already during the measurement.

Use of the tracking analysis measurement system allows frequency analysis of rotational frequency or order.