Subject: Re: streams and groups From: Bruno Repp <repp(at)ALVIN.HASKINS.YALE.EDU> Date: Mon, 14 May 2001 14:38:56 -0700I apologize for replying to John Bates before Al Bregman does; undoubtedly, his reply will be more cogent than mine. But here is my answer to John's questions: > As I understand the discussion here, each clap in a clapper's stream of >claps could be considered to be a group. In Al's terminology, each clap is a unit. I would call it an event. It is a group only in the trivial sense that units and events are groups consisting of a single element. >Or is it that each clapper's >stream of claps is a group? Yes, a stream can be considered a group of a special kind--one that is temporally interleaved with other groups and consists of a substantial number of similar units. >In any case, further parsing of my applause >would reveal that every individual clap is itself composed of streams >and/or groups of smaller identifiable transient events. That seems unlikely to me: Each clap is just a single transient. However, there are more complex auditory events that can indeed be decomposed into smaller elements that are perceptually grouped together. > But when you, Al, finish a presentation, the audience explodes with an >ovation that is a flow of hundreds of homogenized hand-clap sources. You >can no longer pick out the streams and groups. The applause you get is a >single amorphous spatially distributed stream of noise. What happened to >the groups? And is it important to know this? I have never been in this situation (there is usually total silence after I finish a talk), but I would say the mixture of sources contains a large number of potential streams that the listener's perceptual system is unable to segregate. The sources and streams are physically there but difficult to detect. By placing a microphone a few inches from the hands of any individual clapper, the stream of his/her claps can be isolated and made perceptible. --Bruno Bruno H. Repp Research Scientist Haskins Laboratories 270 Crown Street New Haven, CT 06511-6695 Tel. (203) 865-6163, ext. 236 FAX (203) 865-8963 e-mail: repp(at)haskins.yale.edu