Lab of Acoustics Sensing and Information Processing


Spatially enveloping reverberation in sound fixing, processing, and room-acoustic simulations using coded sequences

Acoustic environments in enclosures consist of direct sound from the sound source(s), early reflections and late reverberations. The direct sound and early reflections are predominately responsible for the auditory impression of apparent source width (ASW). The late reverberations are primarily responsible, in addition to impression of spatial sizes, listener envelopment (LEV). In order to achieve artificial reverberation, for naturally enveloping auditory reverberance, this patent-pending project has been focusing on well-controlled, easy to generate reverberation tails using coded sequences (reciprocal maximal-length sequences). When shaped properly, in terms of spatial characteristics and time-frequency characteristics, not only can a natural sounding enveloping reverberance be achieved auditorily but its perceived spaciousness can be controlled in any desired step.

Bayesian inference in architectural acoustics, acoustics detection, and porous material estimations

In architectural acoustics, sound energy analysis has been a primary but challenging task, particularly in single-volume enclosures where sound absorption materials are not evenly distributed, and/or diffusely reflecting surfaces are not sufficient. In addition, many performing arts spaces increasingly employ secondary reverberation chambers coupled to the main floor. In those situations, both single-sloped or multi-sloped sound energy decays can be observed. This research is dedicated to advanced analysis methods using Bayesian probabilistic inference to detect the number of slopes to estimate relevant decay parameters.

Bayesian inference has also been applied in detecting buried objects in the ground using model-based approaches, in estimation of acoustics parameters of porous materials. This is on-going research both in architectural acoustics, physical acoustics and signal processing in acoustics. Since the establishment of the Program in Architectural Acoustics this research has led to a large number of journal publications and paper presentations at national and international conferences.

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