Room acoustical measurements and architectural documentation of auditoriums in Berlin considering the speech intelligibility in dependence of spatial distribution of sound fields

Measurements of spatial room acoustical impulse responses were performed to provide a database for the examination of speech intelligibility (SI) in real rooms. As is well known, the spatial distribution of reflections can influence the SI, especially in reverberant rooms. Nevertheless, the qualitative and quantitative dependences are mostly unknown. Room acoustical measurements thus were realized using a dodecahedron loudspeaker for measuring reverberation time, an interference-free loudspeaker with omnidirectional characteristic for recording impulse responses, and an artificial speaker and a dummy head microphone for measurements of SI criteria and recording of logatom syllables. A specially constructed spaced four-capsule microphone in tetrahedron arrangement was used for measuring also. The four-microphone analysis technique can recognize intensity and direction of the early reflections [Odjija and Krämer (1999)]. Results of the measurements will be documented and published on a CD-ROM, together with the architectural data of the auditoriums. First results of the room acoustical measurements are presented. Prior studies have shown that reproducing the measured binaural cues with headphones does not influence the SI significntly. Subjective measurements of SI and analysis of spatial dependences will be performed in a second stage of the project.