Kevin, hi.
Your example can be very simply done with organ stops, or their
digital equivalent, and you can do it 'on the fly'. Taking any
'note' that consists of various harmonics in varying proportions. If
you set up the harmonics then just hit the key, as it were, - the
usual perception is of a unified note having a specific timbre; if
you gradually shut the stops (take out the harmonics) whist keeping
the key pressed, the perception is of a change in timbre (and
usually of perceived loudness - and, in certain acoustic
circumstances, some report a change of source-perceiver distance
[range]). Do the opposite, and most people can 'hear out' at least
some of the separate harmonics; a little bit of practice (just a few
times) and performance improves. In fact, if you let the note off,
then on again, people continue to hear out the separate harmonics.
What I don't know is how fast that effect would fade: 2mins, 10mins,
next day?. Also, I don't know how transferable, from one note to the
other, and whether the elapsed time between the cessation of the
note with harmonics correctly heard out, and the onset of a new note
with similar harmonic (and amplitude) structure - ie same timbre,
different note - does it go back to being a unified note after some
unspecified elapsed time?
Another way of saying that "...it's all memory" is to say that a
fundamental purpose of perception is the comprehension of ongoing
contexts - which encapsulates the way one understands a sentence,
for that matter. The reason for putting it this way is that it's
(semantically at least) much easier to characterise how perception
is largely 'aimed at the future', so the ongoing cognitive
representation of context is what throws up predictions, occasioning
increased attentive cognitive load when predicted and actual
(incoming sensation) vary. Put this way, perception isn't of the
present at all; real-time sensory input facilitates error correction.
Regards
ppl
Dr Peter Lennox
Director of Signal Processing and Applications Research Group (SPARG)
School of Technology,
Faculty of Arts, design and Technology University of Derby, UK
p.lennox@xxxxxxxxxxx
(01332) 593155
http://sparg.derby.ac.uk/SPARG/Staff_PLX.asp
-----Original Message-----
From: AUDITORY - Research in Auditory Perception [mailto:AUDITORY@xxxxxxxxxxxxxxx
] On Behalf Of Kevin Austin
Sent: 23 August 2009 16:30
To: AUDITORY@xxxxxxxxxxxxxxx
Subject: Perception as memory ...
From my reading, I am now far into semantics with this. In my view,
greatly simplified, perception is memory, but I'm a slow learner in
this matter too.
In the training and development of [sonic] ear-training skills, my
experience is that perception is memory (neither term here am I
defining ... sorry). If 'perception' can be developed, I feel that
this development is a matter of memory development, and the associated
aspects of memory that relate to categorization. If the listener has
only one 'word' (category) for noise, then I have found that the
individual may note "different" noises, but not have a way of
categorizing them. Their category 'grid' is too large to respond with
identification.
For example, say, in musical ear-training, a student regularly
confuses the perfect fourth and the perfect fifth. When played one
after another, they note that they are different, but cannot
'remember' which is which.
For just over a year I have been working at the millisecond and almost
the sample level in editing sounds. Now some 20,000 or more edits
later at the sample / ms level, I speak of my hearing being "faster";
I require much less time to pick up repetition (even non-patterned
repetition), and patterns, than I did before my many hundreds of hours
of (self-imposed) micro-editing training.
Has my 'perception' improved; is my perceptual 'grid' much finer, and
with more experience, does my memory now have a greater number of
categories -- greater precision, accessed much faster. The model I
currently use is that it is "all memory". If the stimulus does not tap
into memory, it is 'invisible'.
One way I demonstrate this with groups is to play a 10 note chord (*)
on a piano, which is heard as an integrated whole by most of those who
hear it. I play the third note from bottom note (a D in this case),
and ask if it was in the chord. Most people can't tell -- they can't
remember (or perhaps cannot 'perceive' -- segregate it from the
complex).
I repeat the D a few times, and play the chord again. Some people may
report hearing it. Most don't.
The next step is to the play the D very loud (ff), and one second
later, play the rest of the chord very quietly (pp), for 2 seconds. I
lift my hands from the other notes of the chord, and the D continues
to sound. This I repeat a few times. Most report being able to 'hold
onto' the D through the sounding chord.
Following this, the time between the D and the chord shortens, and the
"rest of the chord" is played louder and louder. The D is slowly being
placed into the integrated mass of the chord -- the listeners'
memories (for the D and its segregation from the chord) is being
improved.
After about 2 minutes, I return to playing the 10 note chord, and ask
if they are able to hear (segregate) the D from the integrated
structure. Many (many) more report being able to do so.
Has the(ir) perception improved? Will they be able to do this with
other sounds?
My interpretation of my experience here is that they have learned a
technique for the refinement of their memory, but in the colloquial, I
refer to an improvement in their perceptual ability.
Best
Kevin
(*) The chord is, ascending: G Bb D F# A C E G# B C# , the
first 10 notes of the row of the Alban Berg Violin Concerto.
Date: Sat, 22 Aug 2009 11:33:12 +0200
From: Christian Kaernbach <auditorylist@xxxxxxxxxxxx>
Subject: Re: Infrapitch
Dear List,
... In my view, it has more the characteristics of memory than of
pitch perception.
... The introspective sensation when doing so is definitively that
of "remembering", not of "perception".
... It is true that periodicities around 2 Hz (0.5 s) evoke a
"perception" that is different from that of non-repeating noise. I
believe that it is memory that helps to detect some statistical
fluctuations in that noise that otherwise would pass unnoticed. In
other words, memory is altering perception.
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