ENERGY DEGRADATION OF SOUND WAVES OF DIFFERENT FREQUENCIES

Abstract

The specific mechanisms present in sound wave propagation models are of interest to many fields. In this sense, determining the energy degradation of sound is fundamental to the production of knowledge. In this work, we will analyze the attenuation of sound intensity as a function of distance considering different frequencies. We used a 100 Watt RMS source in a wide corridor of the IFRJ, Rio de Janeiro Campus, at a time when no activity was being carried out. Thus, we evaluated the sound intensity emitted from the source every 50.0 centimeters using a decibel meter. Intensity measurements were taken from the vicinity of the source to a distance of 15.0 meters, totaling 30 measurements. We used three different frequencies for each of the 30 measurements. The first was 400 Hertz, the second a frequency of 1600 Hertz, and the last at the beginning of the spectrum considered high-pitched for humans, at 3200 Hertz. These results were graphically projected to compare whether the attenuation of sound intensity with distance is frequency-dependent. We performed two adjustments with different functions for each set of measurements of the three frequencies in order to compare whether attenuation can be observed in the two models. From these adjusted functions, we compared the attenuation of sound intensity using their derivatives.