MARCS Research Seminar

Professor Sue Denham from School of Psychology (Faculty of Science and Technology), Plymouth University is presenting "Auditory scene analysis: a competition between auditory proto-objects?"

Abstract: The auditory system is faced with the difficult task of making sense of the intricate and complex patterns of pressure vibrations in the air around us and interpreting them in terms of the nature of our surroundings and the sound emitting behaviours of objects within the environment. Although this task of auditory scene analysis is of fundamental importance many questions remain both at the cognitive and the neural level. Much of auditory neuroscience has concentrated so far on feature selectivity and the topographic organisation of features, yet many sound sources can only be recognised from the pattern of sounds that they emit, and not from the individual sound events that make up their emission sequences. Thus it is important to consider how individual sound events are linked, and what form this representation might take. We propose a new model of auditory scene analysis, at the core of which is a process that seeks to discover predictable patterns in the ongoing sound sequence. Representations of predictable fragments are created on the fly, and are maintained, strengthened or weakened on the basis of their predictive success. Auditory perceptual organisation emerges from the competition between these representations (auditory proto-objects). Rather than a global interaction between all currently active proto-objects, competition is local and occurs between proto-objects that predict the same event at the same time. The model has been evaluated using the auditory streaming paradigm, and provides an intuitive account for many important phenomena including the emergence of, and switching between, alternative organisations, the influence of stimulus parameters on perceptual dominance, switching rate and perceptual phase durations, and the build-up of auditory streaming.