Analysis of the Dependence of the Apparent Sound Reduction Index on Excitation Noise Parameters

Abstract

In acoustic practice, established methods of measuring the acoustic properties of partition structures are used. Recommended procedures and means can be found in technical standards, but practice suggests that measurement results may also depend on measurement conditions. These procedures leave the choice of noise type, frequency interval examined, and excitation interval on the measurer. The aim of this research is to determine which parameter has a significant effect on the results, and to quantify the extent of this effect. We examined the type of noise, the frequency band of the sound passing through the partition structure and the excitation interval of the diffusion field in the rooms (hereinafter referred to as “excitation interval”). During the research, we conducted a number of repeated, statistically significant measurements, which we first evaluated by classical methods used in acoustic practice. We subjected the obtained results to a thorough mathematical analysis. Evaluation of the results shows that some measurement conditions significantly affect the resulting values, especially in the low-frequency spectrum. One of the most important elements which has an effect on the results is the type of excitation noise, which, when assessed in the source room, excites the diffuse sound field, and its transmission through the considered partition structure is measured. The significance of the investigated frequency interval was also demonstrated.

Study of Noise Effect of Slag Storage Technology on Surrounding Environment

“…due to their distance from the residential area, do not have any impact on the assessed protected area [13,14].…”

“…Deskulling of the slag pots is carried out in summer at the reference time interval day and evening (6 am-10 pm) and, in winter, also at the reference time interval night (10 pm-6 am). Traffic noise associated with the operation of the metallurgical plant is not subject to assessment-car and rail traffic routes are located away from the assessment area and, due to their distance from the residential area, do not have any impact on the assessed protected area [13,14].…”