Measuring Sound Insulation under Extreme Conditions using Deconvolution Techniques

To compare the sound insulation performance of a building element with the given requirements, measurements have to be done. Generally, a broadband noise source is used, according to international standards. This method does not always work in practice due to high sound insulation values or high background noise levels. From a practical point of view it is very inconvenient or even impossible to perform an accurate sound insulation measurement for all frequency bands. A solution to this problem can be found in deconvolution techniques using MLS or sweep signals. It is possible to increase the signal to noise ratio using these techniques by averaging measurements and spreading out the spectral sound energy in time. As a result an efficient use of available sound power is possible. In a laboratory it can be investigated how to use MLS or sweep as a source signal and deconvolution as a measurement technique to obtain the sound insulation under noisy conditions. This has been investigated under moderately reverberant conditions, presented at the conference 'Acoustics'08 Paris', while this paper describes the same investigation under more extreme conditions.