A comparison of results with different logging rates using ISO/PAS 1996-3:2022

Noise with prominent impulsive sound is more annoying than continuous types of noise (without impulses) with the same equivalent sound pressure level. Therefore, an adjustment is added to the measured LAeq if prominent impulsive sound is present. In ISO 1996, three categories of impulsive sound are defined, with adjustments for each. The list of sources of impulsive sound for each category is incomplete. ISO/PAS 1996-3 defines an objective method to measure the prominence of impulsive sound relative to residual sound. This can be used to categorize the impulsive sources, complementing the ISO 1996-2 environmental noise assessment method. The method is based on logging LpAF with 10-25 ms time intervals. Short-term LAeq (e.g. 10 ms), although not preferred, can be used to compute these values. 100 ms sampling is permitted for surveys and screening. Annex A of ISO/PAS 1996-3 PAS encourages further research to support the development of a full ISO standard. This includes the application of real-world sources assessed at receiver locations including typical signal to residual noise ratios. This paper describes such a study under these conditions that investigates the impact of the time intervals on results.