Design and implementation of a listening room in accordance with the ITUR BS 11161 standard

As part of the project “Advanced Audio Processing (AAP)” [1] the work package ‘Expert listening panel for sound quality evaluation’ focuses on the problems and challenges of assessing professional audio applications and equipment. While a lot of test centers exist for objective measurements, the lack of facilities for the realization of subjective listening tests makes it difficult to obtain repeatable and reproducible results. The fields of application and the products being tested in the facility which is subject to this work are: Sound quality of microphones for studio and automotive applications; from in-ear headphones to professional studio headphones, etc.; Spatial attributes of sound fields; Speech quality (e.g. of voice recorders during playback); Data representation through sound (e.g. assessment of sonified signals). The basic problem with listening tests in general is the complex interaction between stimulus and the resulting sensation. In most cases, the scientific interpretation of such stimuli is only feasible by interrogating a bigger group of listeners. If the obtained results are to be statistically representative for the entirety of all possible listeners, the group of test listeners must be chosen carefully. For this purpose, a group of professional listeners - the so-called listening panel - is needed in order to yield consistent results. Moreover, standardized listening test interrogation structures need to be maintained to achieve a repeatable assessment procedure. The task of selecting and training a group of professional listeners and the challenge of implementing a standardized assessment procedure has been distributed among the research partners and is not subject to this work. It would desirable, especially for the industry, to create a facility that is as neutral as possible, which should then receive tasks from the industry. As a final goal, it would be desirable to obtain a test location that is able to deliver some kind of certification similar to those of Dolby or THX at the moment.