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Re: perceptual learning

Interesting. This is just a thought that came to mind.

In music the 'shape' is associated with intensity as a function of
time-- crescendo/decrescendo for example gives the impression of shape.
Also perhaps with acceleration and ritard of tempo. Spectral shape is
clearly associated with 'color'.

Also, in sound there's a clear and natural perception of space. IIDs and
ITDs give a normal hearing listener a clear spatial picture. So, if an
object in the visual space were turned to sound for a blind person--
would it then not be most useful to have the sound emanate
(perceptually) from the location of the object?

I'm sure these mappings could get most complex, from the programming
standpoint. Peter has height mapped to frequency and left to right
mapped to time (would this be right to left in some countries?) At any
rate, it wouldn't be tremendously difficult with headphones to have that
image shift from left to right acoustically as it does visually.

Music and speech could be considered extended dynamic profiles. Persons
who are blind may well have a heightened auditory sensations (since all
the brain mass most people used to see could be used by the other
senses), so there's no telling how much a blind person could learn about
a new sound genre -- if they're motivated to learn it-- preferably a
task that's somewhat intuitive, enjoyable and informative.

Ward Drennan
MRC Institute for Hearing Research, Scottish Section
Glasgow Royal Infirmary, Queen Elizabeth Building
Glasgow G31 2ER  UK
Tel: (int'l) + 44 141 211 4856
Fax: (int'l) + 44 141 552 8411

-----Original Message-----
From: Peter Meijer <peter.b.l.meijer@PHILIPS.COM>
To: AUDITORY@lists.mcgill.ca <AUDITORY@lists.mcgill.ca>
Date: Sunday, April 02, 2000 1:15 PM
Subject: Re: perceptual learning

>Spectral 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
>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