Subject: Re: Auditory wheel From: Bob Carlyon <bob.carlyon@xxxxxxxx> Date: Fri, 19 Mar 2010 12:37:17 +0000 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>I think that what we need in order to understand and resolve these issues is a really good mechanical cochlear model. Suggestions, anyone? Bob Leon Van Noorden wrote: > 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 -- Dr. Bob Carlyon MRC Cognition & Brain Sciences Unit 15 Chaucer Rd Cambridge CB2 7EF England Tel: +44 1223 355294 Fax: +44 1223 359062 www.mrc-cbu.cam.ac.uk/hearing