The sources of error in measurement of sound transmission loss

Since the first time sound intensity measurements were used in determining the sound transmission losses of partitions more than 15 years ago, a number of investigations have indicated systematic deviations between results obtained with the traditional method and intensity-based estimates. The various sources of error of both methods have been analysed and examined experimentally. Both types of measurements can be subject to several fairly small systematic errors of comparable size. However, the conclusion of this investigation was that there are no systematic deviations if the measurement procedures are very careful.
This investigation was initiated during Ding Hui's stay at the Department of Acoustic Technology in 1993.