Transformações das edições da NBR – 10.151

Currently, NBR-10.151 is in its third edition and, through changes in its content, changes in approaches, terminology objectification and technical complexity can be seen throughout its validity, in the face of losses, gains, coherence and disparities in its application in the acusticosphere to be taken care of. This work presents a comparative analysis of the three editions of the aforementioned standard, pointing out these most significant aspects of the transformations that took place in the text and their repercussions. In the case of losses, for example, suppression of the assessment feature taking into account residual noise, as well as estimates of public reaction to noise. In the intermediate edition of the standard, the understanding and application of the standard was more accessible to different professionals, not exclusive to engineering, who joined efforts for a legal and adequate acousticosphere, and this was not maintained in the most recent edition, intimidating this multidisciplinary cooperation. Also in terms of losses, there was emphasis on restricting the external criterion and resorting to the internal criterion in a very specific situation. In terms of gains, there was an improvement in the quality of the acquisition of acoustic data, whether in terms of equipment and procedures for measuring and analyzing sounds, updating terms and descriptor symbols in line with acoustic terminology, such as the introduction of descriptors involving longer periods. broad assessments. As a disparity, there are the misconceptions regarding the use of NC curves not consistent with the original proposition of their application and the use of a wrong value of  in the estimation of Ldn.