In-situ estimation of sound Transmission Loss using a scanning sound intensity P-U probe
The assessment of sound insulation by acoustic intensity measurements is a versatile alternative to the standard two-room method, particularly in the presence of flanking transmission or when it is necessary to show local contributions. An extension of traditional intensity-based methods of estimating Sound Transmission Loss (STL) can be achieved by using measurements in both sides of the sample under investigation via a sound visualization technique such as Scan & Paint. Such approach is suitable for in-situ tests, avoiding the necessity of a reverberant source room and an anechoic receiving room. Sound pressure maps, acoustic particle velocity and sound intensity can be used to describe the acoustic power transmitted through a partition or element. Furthermore, visual representations of the acoustic field over the investigated area can reveal structural weakness or leakages, key information for applying appropriate noise control strategies. In this paper, scanning sound intensity measurements with a PU probe are performed in both sides of the sample to estimate sound transmission loss. Results are validated via comparisons with estimations obtained through the standard two-room method. It is demonstrated that the in-situ estimations of sound transmission loss are in good agreement with the standardized procedure. In addition, sound maps provide detailed information of both excitation distribution in the source room and the most critical emission points in the receiving room.
Rodriguez-Fernandez, C. and Fernandez Comesana, D., 2017. In-situ estimation of sound transmission loss using a scanning sound intensity pu probe. Simpósio de Acústica e Vibrações–Coimbra.