The DENORMS Round Robin Test aims to study and improve the techniques used to determine the sound absorption coefficient of materials. Within this framework, samples taken from the same batch have been tested in both reverberation room and impedance tube. The latter technique presents some practical challenges that make the results strongly dependent on the specimen preparation and set-up. The purpose of this paper is to compare the results obtained fom the same material tested with different sample configurations. The tests have been carried out using a transmission tube, according to the method outlined in the ASTM E2611-09 standard. The results obtained for the different parameters provided by the test are taken into account and discussed.
