Room acoustic texture: a methodology for its quantification
Proceedings of the ICA congress
Room acoustic texture is defined by Beranek as the subjective impression listeners derive from the temporal and amplitude patterns of early reflections, at the receiver's locations inside the room. Traditionally, room acoustic texture was qualified by visual inspection of the room impulse responses (RIR) or counting reflection´s peaks. Taking into account that the reflections in the later part of the RIR follow a Gaussian probability distribution and are totally mixed, we define the early
... ine the early reflections as every amplitude outlier present in a RIR, and mixing time as the instant when their cumulative energy reaches 99% of their total energy. To find outliers amplitudes, we proceeded to cancel the decay of the energy time curve (ETC) under analysis using a mobile median filter. Then, the particular echo density function (edf) is defined as the decay-cancelled outliers cumulative energy, over time. From this processing, a group of descriptors were defined that jointly describe the room acoustic texture, at one point in the sound field. Among these descriptors are the mixing time, expected texture and distance between models. Applications of these descriptors and their spatial standard deviation in rooms seem to be very broad, describing their temporal fine-structure.