The auditory system must separate an acoustic mixture in order to create a perceptual description of each sound source. It has been proposed that this is achieved by a process of auditory scene analysis (ASA) in which a number of streams are produced, each describing a single sound source. Few computer models of ASA attempt to incorporate attentional effects, since ASA is typically seen as a precursor to attentional mechanisms. This assumption may be flawed: recent work has suggested that attention plays a key role in the formation of streams, as opposed to the conventional view that attention merely selects a pre-constructed stream. This study presents a conceptual framework for auditory selective attention in which the formation of groups and streams is heavily influenced by conscious and subconscious attention. This framework is implemented as a computational model comprising a network of neural oscillators which perform stream segregation on the basis of oscillatory correlation. Within the network, attentional interest is modelled as a gaussian distribution in frequency. This determines the connection weights between oscillators and the attentional process- the attentional leaky integrator (ALI). A segment or group of segments are said to be attended to if their oscillatory activity coincides temporally with a peak in the ALI activity. The output of the model is an ‘attentional stream’: a description of which frequencies are being attended at each epoch. The model successfully simulates a range of psychophysical phenomena. Furthermore, a number of predictions are made and a psychophysical experiment is conducted to investigate the time course of attentional allocation in a binaural streaming task. The results support the model prediction that attention is subject to a form of ‘reset ’ when the attentional focus is moved in space. Acknowledgements The inspiration and initial psychophysical data upon which this work is based came from a presentation

A model of auditory grouping is described in which auditory attention plays a key role. The model is based upon an oscillatory correlation framework, in which neural oscillators representing a single perceptual stream are synchronised, and are desynchronised from oscillators representing other streams. The model suggests a mechanism by which attention can be directed to the high or low tones in a repeating sequence of tones with alternating frequencies. In addition, it simulates the perceptual segregation of a mistuned harmonic from a complex tone.

In this paper, we argue that music cognition involves the use of acoustic and auditory codes to evoke a variety of conscious experiences. The variety of domains that are encompassed by music is so diverse that it is unclear whether a single domain of structure or experience is defining. Music is best understood as a form of communication in which formal codes (acoustic patterns and their auditory representations) are employed to elicit a variety of conscious experiences. After proposing our theoretical perspective we offer three prominent examples of conscious experiences elicited by the code of music: the recognition of structure itself, affect, and the experience of motion.

Abstract not found

We present an overview for the study of auditory perception and scene analysis through the three main approaches researchers have used to study perception in general: behavioral, physiological, and computational. At the behavioral level, we discuss the principles and origins of auditory scene analysis, and establish the relationship between auditory scene analysis and auditory masking. Within auditory masking, we note the coexistence of informational and energetic masking, and utilize the ideal time-frequency binary masks in a series of speech intelligibility experiments to isolate the energetic component of speech-on-speech masking. At the physiological level, we propose the adoption of the two-dimensional time-frequency oscillatory correlation representation as a main representation in auditory perception, after reviewing several of the theories and experiments in neurophysiology in effort to find its support. Finally, at the computational level, we extend an existing implementation of oscillatory correlation, LEGION [144], to simulate the major behavioral principles in alternating-tone sequences. Most notably, the decision boundaries of the temporal coherence boundary (TCB) and fission boundary (FB)

The formation of coherent percepts requires grouping together spatio-temporally disparate sensory inputs. Two major questions arise: (1) is awareness necessary for this process; and (2) can non-conscious elements of the sensory input be grouped into a conscious percept? To address this question, we tested two patients suffering from severe left auditory extinction following right hemisphere damage. In extinction, patients are unaware of the presence of left side stimuli when they are presented simultaneously with right side stimuli. We used the ‘scale illusion ’ to test whether extinguished tones on the left can be incorporated into the content of conscious awareness. In the scale illusion, healthy listeners obtain the illusion of distinct melodies, which are the result of grouping of information from both ears into illusory auditory streams. We show that the two patients were susceptible to the scale illusion while being consciously unaware of the stimuli presented on their left. This suggests that awareness is not necessary for auditory grouping and non-conscious elements can be incorporated into a conscious percept.