Resumen de Modal energy density influence on in situ sound reduction index measurements
Sebastián Rolón Carreras, Adrián Montoya, Ricardo Pesse
Sound insulation fulfillments inspection on building constructions and industrial noise control is fundamental for the advances on noise environmental laws. The traditional pressure-based methods of measuring sound reduction indexes require reverberant rooms for their implementation, and the real behavior of these rooms at low frequencies is not exactly as the diffuse field model assume. Therefore, there is tendency to overestimate the sound insulation of a partition on those frequencies. Transmission loss measurements on two different situations according to ISO 140-4 were done, and through a finite element method, the low-frequency modal behavior of the rooms was analyzed. Considering the receiver room modal density on sound transmission loss measurements increased the method's precision by getting closer to a real diffuse field case. The results for each situation were verified using the sound intensity method according to ISO 15186-2, which due to its characteristics does not need this consideration.
