Sound Transmission Loss of Building Materials

Sound transmission loss (TL) is a measure of the sound energy that goes though a building elements such as walls, windows or door system.  The transmission loss is generally expressed as a single number rating as the Sound Transmission Class (STC) of the building material.  Industry test standards ASTM E90 and ISO 140 are common methods for measuring the sound transmission loss of a building element.

Sound transmission loss is measured by inserting the building element between two reverberation chambers.  The Source chamber contains a sound source that introduces broadband noise and the highly reflective walls in the room create a diffuse field, meaning the source doesn’t seem to come from any specific location. A diffuse field is also created in the Receive chamber, by the noise transmitted through the material being tested. The fields in the Source and Receive chambers are measured and compared to calculate TL.

The staff at VIacoustics are intimately familiar with these tests. We can help you build your chambers from the ground up, outfit your existing chambers with instrumentation and software, and train you to use all of it.