Subject: Re: perceptual learning From: Peter Meijer <peter.b.l.meijer(at)PHILIPS.COM> Date: Sun, 2 Apr 2000 14:12:55 +0200Spectral shape perception is in my personal opinion one of the most promising inroads towards the analysis of perceptual learning above the "microscopic" level. Indeed I recommend the work of David Green and Ward Drennan (and a few others) on spectral profile analysis and the learning aspects of that, and would like to take this opportunity to plead once more for much more follow-up work in that direction. Not only for a better understanding and improvement of cochlear implants and other hearing aids, but also to learn more about perceptual and learning issues for blind people accessing purely visual information through sound representations. For instance, see yesterday's online article at http://www.suite101.com/article.cfm/disabilities/36515 which, I'm glad to read, warns for the steep learning curve in (perceptual) learning for this cross-modal approach. The technology is now largely there, but our understanding of the=20 perceptual and learning issues is not at all at a comparable level. This is unsatisfactory. The consequence is that we are working in parallel on exploration through blind volunteers while further developing the technology, but we largely lack an understanding of what the brain can learn to make of auditory images, what the role of brain plasticity and a critical age would be, or how we should devise a training program for best and quickest results. This would not be a luxury, because a steep learning curve can be quite frustrating. Some blind people nowadays use this technology to hear online stock charts and the like, but that is trivial as compared to what the technology will allow for if "only" human perception and learning can be brought to match what's there from a technical perspective (even after we consider the basic limitations represented by JNDs, critical bands and forward and backward masking). I'd like to see spectral profile learning and analysis applied to the perception and recognition of for instance various more or less geometric shapes presented "spectrographically" in sound. It is easy to parameterize such shapes and sets of shapes for quantitative studies. This will allow for a scientifically decent methodology that can systematically extend the work on auditory profile analysis towards higher levels of human abstraction with respect to the information content in the sound. Speech and music seem less suited to that (most people except very young childern have already mastered at least one language), while many other classes of sounds (the usual beeps and noises that have been studied so extensively in the past century) have in my view no obvious route from the "microscopic" to any worthwhile higher levels of abstraction in human information processing. I hope my arguments are not too controversial, because that could render them counterproductive. Best wishes, Peter Meijer Seeing with Sound - The vOICe http://www.seeingwithsound.com/voice.htm =