Final Thesis

Objective and subjective analysis of room acoustics in open-plan offices

Master Thesis of Xu Xinya

In day-to-day work, people are surrounded by various noises that can significantly affect cognitive performance and acoustic satisfaction. This acoustic perception and its effect are caused and influenced by various factors . Therefore, a diverse acoustic spatial analysis, from the objective as well as the subjective aspect, is needed. In this thesis, open-plan offices were measured with aurally-accurate methods and their acoustic properties were analyzed. On the one hand the room acoustics of the rooms were examined, on the other hand the acoustic environment in the presence of persons was measured for the psychoacoustic analysis (in-situation measurements) . Besides an omnidirectional microphone the ITA artificial head was used to get an aurally-accurate evaluation. In addition, the subjective perception was examined using questionnaires, which were filled out by the persons present in the rooms during the in-situation measurements. Subsequently, correlations between roomacoustic and psychoacoustic parameters, as well as between objective and subjective results were evaluated. D2,s has correlated better than T20 and T30 , both with the subjective perception of the acoustic environment and with the subjective estimates of the reverberation time. In terms of speech intelligibility, TD and Tp correlated with voices and laughter of colleagues and with the subjective estimates of speech intelligibility. I ACC showed significant correlations with binaural loudness and with the subjective perception of the voices and laughter of colleagues. Several correlations between sharpness and subjective perceptions were determined, so the noise was more noticeable, since greater sharpness usually causes more annoyance. In addition, it was demonstrated that the objective parameters could be subjectively evaluated. However, the loudness and the speech intelligibility of the doser colleagues were estimated better than those of the colleagues in the further distance. There was a significant difference between monaural and binaural values for ST land loudness, but no significant difference for sharpness.