In this paper a study of the sound transmission loss (PT) in various everyday materials such as styrofoam, cardboard, glass, cotton and sisal is performed. The experimental setup consists of two sound level meters and an absorbing anechoic chamber. It is shown in detail how to build with inexpensive materials the anechoic chamber used to measure the PT. From the difference in the nominal measures of the two sound level meters located inside the anechoic chamber the PT data are recorded. With the PT data as a function of frequency and sweeping the frequency spectrum in third octave bands from 100 Hz to 5.000 Hz, the different curves that characterize the materials acoustic behavior are plotted. We show the PT dependence with the density and structure of the material used to attenuate the sound. This experiment can be used in physics or engineering courses, like waves or materials characterization, for students to explore the sound insulation capability of a wide variety of materials readily available in their environment.
transmission loss; anechoic chamber; sound absorption; attenuation
