Sound Flanking Transmission: Assessment by a Slit Method

The aim of this study is to understand the effect of flanking transmissions on room sound transmission. For this purpose, three tests have been carried out in-situ in three rooms with similar layout. The assessment method consisted of cutting one or two slits on the source room walls and measuring before and after cutting. Measurements of air-borne sound insulation, impact sound isolation (with impact on the source room lateral walls) and acceleration measured on the receiving room lateral walls, were made. The slit prevent transmission of wall vibration, originated by sound excitation, and thus allows us to quantify the associated flanking transmission. It is also shown that, if the slit is sealed with silicone, there is almost no change in the results, and it can be concluded that it is the difference in impedance, which prevents transmission.