NOTE: This website is an archived copy of Al Bregman's personal website, created with the permission of Abigail Sibley and Christopher Lyons. Copyright (c) 2008 Al Bregman.

Audio demonstrations of auditory scene analysis

Overview

Sequential and simultaneous integration.

There are at least two dimensions of perceptual grouping. The first is sequential, in which bits of auditory data are connected across time. An example would be connecting the parts of the same melody together. The second is simultaneous, in which pieces of data arriving at the same time are either integrated or segregated from one another. An example would be the awareness of three notes as separate entities in a chord, or the segregation of one talker from another. We begin by illustrating sequential integration (Demonstrations 1 to 17). In a second set (18 to 24) we illustrate the integration or segregation of simultaneous components.

The old-plus-new heuristic.

The third group of demonstrations (25 to 37) illustrate the "old-plus-new heuristic" which helps in the decomposition of a mixed spectrum by comparing a complex spectrum with an immediately preceding simpler one. This heuristic can also be seen as a case of competition between sequential and spectral organization.

Most of the already mentioned demonstrations will work quite well without headphones, i.e., over loudspeakers, as long as the room is not too reverberant. If it is, try positioning yourself close to the speakers. However, in the fourth set, Demonstrations 38 to 41, we present a number of dichotic demonstrations which do require headphones.They illustrate each of the previously listed three categories of perceptual organization, but use spatial cues to control the organization.