Subject: Re: Auditory wheel From: Leon Van Noorden <leonvannoorden@xxxxxxxx> Date: Fri, 19 Mar 2010 02:17:56 -0500 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Now I start to think about it is clear that timbre perception is our capacity to recognize how a sound is generated and through which filters it comes to our ear. In the good old days of the Institute for Perception Research in Eindhoven we had a demonstrator of the "klinker driehoek" (vowel triangle). This triangle lays in the x-y plane of which the two dimensions are the first two formants of vowels. In this triangle you can of course draw a wheel. The demonstrator was implemented on 80 by 80 cm x - y plotter that you could move by hand with a knob at the crossing of the two arms. With some exercise you could speak with it and make sentences like " I owe you ". To day you could easily implement it wit a touch screen and software like max/msp or ableton live. I think this is a fully parametrized space. Bye from Bogota. iPod On 18 Mar 2010, at 17:22, "Michael H. Coen" <mhcoen@xxxxxxxx> wrote: > Hello list, > > We are all familiar with the notion of a visual color wheel, e.g., a > continuous, circular representation of colors in some color space such > as HSV. (Here's a wikipedia page with some visual examples: > http://en.wikipedia.org/wiki/Color_wheel) > > Of course, there are many different color wheels, given that there are > many different color spaces in which to model them. > > I'm looking for the auditory equivalent of a color wheel. Namely, a > parametrized, continuous method for generating a series of sounds that > form a "perceptual loop" that has no perceived gaps. > > I've coded a several of these, e.g., a violin morphing into a piano > morphing into a clarinet, which then morphs back into a violin. They > are all playing middle C and the ASDR envelopes for the generated, > equal-length samples are identical. > > I'm doing this to measure discriminative acuity in distinguishing > sounds > along the auditory wheel, as part of a larger multimodal perceptual > experiment. > > However, what I've found is that people with musical backgrounds have > far greater discriminatory power in separating nearby sounds than > those > who have little training. There are also "unintended" clues, such as > harmonic complexity, which people appear differentially sensitive to. > > Thus, I wonder if there is any work in creating such an auditory wheel > that might be expected to reduce bias due to background and/or > culture. > E.g., using a heptatonic music scale may not be a good idea and sounds > derived from familiar instruments are probably best avoided as > well. I > would like participants to be on an equal auditory footing, so to > speak. > I'll repeat that it is essential that there be a "loop" in the sound > presentation that is not due to a simple repetition of sounds, e.g., a > sine wave rising and then falling in frequency would not be useful. > > Any pointers, suggestions, code, etc., would be most welcome. > > Best, > Michael Coen