Re: streams and groups (Peter Lennox )

Subject: Re: streams and groups
From:    Peter Lennox  <peter(at)LENNOX01.FREESERVE.CO.UK>
Date:    Wed, 16 May 2001 10:10:03 +0100

To find the limit (as below), I rather think you would have to specify a great deal about the acoustic circumstances, as I suspect these would impinge greatly on the matter of 'switching' between hearing disparate sources ('things') and hearing a collective ('stuff'). It seems (intuitively) that a more reverberant listening place would result in fewer 'clappers' required to form a stuff, and a more anechoic (can you have 'more anechoic'?) environment would require more clappers to do the same. In addition, distance of clappers would be relevant, in that, I suspect, normally what would be heard is a 'stuff' (the applause) with a few 'things' (individual clappers) embedded in the front. I do remember a sound engineer telling me that it was normal practice to 'pad out' applause with pink noise, sometimes. So it does seem to be something about the homogenisation of transients due to physical circumstances, which is in large part exrinsic to any particular percipient. The intrinsic part has to do with the degree to which 'signal to noise ratio' can be thought of as having a directional component, and in which case, upper-frequency hearing impairment might move the limit of clap-to-applause switching downwards (other factors being equal). regards, ppl > > I was assuming an impersonal interest in the composition of the > applause. More to the point, there seems to be a certain level at which > our auditory systems decide that the number of clappers (or voices or > raindrops) becomes a single applauding crowd...too many to segregate into > individual sources or groups. (Apparently you and I have not reached that > level.) Has anyone found that limit? > Most such projects now seem, at best, to regard more than two sources as a > crowd. > The problem is significant in devising the algorithm for a real CASA > system. > > - John Bates > >

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