Determination and Display of Spatial and Temporal Room Impulse Responses

Daniel Protheroe , Bernard Guillemin

New Zealand Acoustics, 24(1), pp.24- 32 . (2011).

The acoustical characteristics of a room are traditionally determined using directionless impulse response measurements, the directionless nature of which imposes significant limitations on the kinds of information that can be extracted. Obtaining such information in 3D would permit, for instance, a more detailed analysis of sound reflections to be undertaken. This paper overviews a technique for capturing a room’s impulse response in 3D using a practical mi-crophone array (A-format) and then transforming this data into a Cartesian coordinate system (B-format) so that it can be visualised as an image or video. This 3D impulse response visualisation carries information about sound reflections in terms of sound intensity, spatial orientation and time. A software package has been developed in MATLAB to implement this technique, preliminary results from which will be presented. Enhancements of this 3D visualisation, together with a thorough understanding of the accuracy and robustness of the technique, are the focus of a current study and will be briefly discussed.