Medição de potência acústica de fontes sonoras através dos métodos da pressão e da intensidade

Abstract

In order to analyze and better understand the acoustic phenomenon and some of the current standards related to the theme, measurements of the sound power level of a sound source were carried out using pressure and intensity methods, with four levels of background noise: noise of the environment, 64 dB, 85 dB and 94 dB, in a single environment. For ambient noise, 64 dB and 85 dB, the results obtained met the prerequisites for the validation of the measurements and were not very far from the expected ones, presenting a general difference of less than 1% between the results obtained by the two methods. As for the background noise of 94 dB there was a significant increase in sound pressure and, due to the position of the external noise emitting source in the environment and the characteristics of the environment, resulted a directionality of the external noise source in relation to the source emitting noise, resulting in not meeting the prerequisites for validation of measurement. It was also verified the possibility of using the sound intensity measurement equipment to raise the mean sound pressure level, since this equipment supplies this data, which was used in the calculation of power by the pressure method.