Sound absorption measurement using MLS method. How much is the final result affected by the non-linearities of the measurement chain ?

The measurement of the acoustic properties of a material using impulsive methods can be performed through low-cost instruments, such as computers and good quality soundcards. In the measurement chain an acoustic source and a microphone are also involved. Since they cause most of the non-linearities, these items can be considered the weak link in the chain. In this paper different ways of equalizing the measurement chain are shown and their influence on the final result is discussed.