Sound transmission‐loss characteristics of three‐layer composite wall constructions

The sound transmission‐loss (TL) characteristics of three‐layer composite wall constructions are considered. Analytical models predicting TL were developed for constructions with homogeneous isotropic cores or homogeneous orthotropic cores. Experimental results for composite panels with isotropic and orthotropic cores were compared with analytical predictions with acceptable agreement. A new design process for layered composite panels with high TL was developed. TL values exceeding mass law by as much as 10 dB are achievable. A composite panel was fabricated and provided a verification of the design process. Greater‐than‐mass law TL was obtained. [Work supported by NSF.]