Forward and reverse transmission loss measurements

  • A.C.C. Warnock Inst. for Research in Construction, National Research Council Canada, 1200 Montreal Road, Ottawa, Ont. K1A 0R6, Canada
Keywords: Approximation theory, Automation, Calibration, Data acquisition, Frequencies, Microphones, Standards, Automated systems, Floor plan, Mean difference, Transmission loss


The main methods for measuring sound transmission loss using the two-roo method ASTM E901 and ISO 140∓32 are discussed. Changing the direction of a transmission loss test leads to a change in the STC and other ratings generated. The standard test methods 1,2 require measurements in both directions as a means of improving reproducibility for the test methods. The number of microphone position required for a test in a direction can be reduced to avoid doubling the time for testing.
How to Cite
Warnock A. Forward and reverse transmission loss measurements. Canadian Acoustics [Internet]. 2004Sep.1 [cited 2019Aug.19];32(3):168-9. Available from:
Proceedings of the Acoustics Week in Canada