Perception of Reverberation in Domestic and Automotive Environments

The central topic of this thesis is Reverberation. Reverberation is used as a global term to describe a series of physical and perceptual phenomena that occur in enclosed environments and relate to the acoustical interaction between a sound source and the enclosure. This work focuses on the effects of reverberation that are likely to occur within common listening environments, such as car cabins and ordinary residential listening rooms. In the first study, a number of acoustical fields was captured in a physically modified car cabin and evaluated by expert listeners in a laboratory, using a spatial reproduction system. In the second study, nine acoustical conditions from four ordinary listening rooms were perceptually evaluated by experienced listeners. The results indicated the importance of decay times in these types of enclosures, even in these theoretically short and nondominant quantities. It was shown that a number of perceived attributes were evoked by the alterations of the fields both within the same enclosure as well as between different ones. The studies made use of a novel assessment framework, which forms a significant part of this work. The proposed framework overcomes previously identified challenges in perceptual evaluation of room acoustics, relating to acquisition and presentation of the acoustical fields, as well as the perceptual evaluation of such complex sound stimuli. It was shown that this framework was able to decompose the phenomena that underline the perceived sensations across assessors. The related multivariate analysis techniques employed the conjoint interpretation of both the physical and perceptual properties of the fields in a factorial space and effectively enabled the direct investigation of their relationships. Overall the work described in this thesis contributes to: (1) understanding the perceptual effects imposed in the reproduced sound within automotive and residential enclosures, and (2) the design and implementation of a perceptual assessment protocol for evaluating room acoustics. The thesis contains two parts. In the first, the background and rationale of the research project are presented. The second part includes four articles that describe in detail the research undertaken.