15. março 2022

How to Measure Nuisance Sounds

How to Measure Nuisance Sounds

The primary goal of a sound level meter is to measure sound pressure levels. Upper limits for these levels are generally prescribed by law. However, there are also noises that are far below any limits, but which are nevertheless perceived as a nuisance. In many cases, such noises do not occur constantly, but only for short periods and at different times, making them perhaps difficult to identify.

The first step is to provide the complainant with a button to press when they hear the annoying sound. The Input Keypad for the XL2 Sound Level Meter fulfils this need. When one of the four buttons is pressed, corresponding markers are placed in the XL2's log file, making it easier to retrieve when post-processing the continuous measurement with the XL2 Data Explorer PC software. With the Advanced Acoustics Package option, an audio recording can be triggered to assist in identifying the noise.

Can you hear that? What?

The human brain has a remarkable ability to ignore sounds that it does not find relevant. If, for example, you work or live next to a railway line, over a period of time you may accept that the sound of regular passing trains is just one of those things, and your brain will ignore them.

On the other hand, the brain also has the incredible, sometimes unwanted, ability to focus on the smallest of sounds, such as a ticking clock when you are trying to sleep. While the law is unlikely to ban all ticking clocks, it can assist with other noises such as music played by your neighbor or the incessant pulsing noise from a wind farm that has just been built up the road. For barely audible sounds, such as an annoying humming sound, there are no legal regulations at all.

Noise Assessment

So it is up to the complainant to choose which noises are a nuisance. Using the Input Keypad in combination with the type-approved XL2-TA meter meets the requirements of the IEC 61672 (USA: ANSI S1.4) standard and provides samples for a legal noise nuisance assessment.

Finding the noise events of interest within a large amount of measurement data is very much simplified if the complainant presses the keypad button when disturbed by a noise event. The Input Keypad is connected directly to the XL2-TA Sound Level Meter by cable. The measured noise emissions are then complemented by the subjective trigger from the complainant.

Faster Analysis with XL2 Data Explorer Software

Each button press is marked in the measurement data log file. When importing the measurements into XL2 Data Explorer software, these markers are displayed and may be analyzed individually or as groups for their levels, time of day, spectral content or alternatively to exclude non-nuisance events from the nuisance calculations.