Fw: Signals, Sound and Sensation

Archived from groups: rec.audio.high-end (More info?)

From my wife, the audiologist.

----- Original Message -----
From: Sherman, Amy D
To: 'John'
Sent: Tuesday, April 05, 2005 4:14 PM
Subject: RE: Signals, Sound and Sensation


Very true & accurate. He's talking about assimilation. It's what our
brains do to compensate for unknown information. Our brains "fill in"
using past learned concepts/pictures/auditory information to make
something recognizable or familiar. We can apply this to visual or
auditory stimuli. Psychology books talk about it, too.

Amy Sherman






--------------------------------------------------------------------------------
From: John
Sent: Tuesday, April 05, 2005 11:26 AM
To: Amy at work; Amy
Subject: Fw: Signals, Sound and Sensation


True?
----- Original Message -----
From: Michael Mossey
Newsgroups: rec.audio.high-end
Sent: Monday, April 04, 2005 8:50 PM
Subject: Signals, Sound and Sensation


I'm reading Signals, Sound and Sensation by Hartmann. Fascinating
book. There's a bit on the topic of "auditory induction." This is
amazing.

If you take a recoding of speech and put silent gaps in it, it become
less intelligible. However, if you fill the gaps with noise rather
than silence, it become intelligible again.

There's a visual analogy on page 122 of the book which shows a scene of
random shapes. There's nothing intelligible in the shapes at all.
Then next to it, there's the same scene, with a continous weaving blob
of dark ink threading its way through the "random" shapes. Suddenly
you see that the random shapes are actually recognizable letters
partially obscured by the blob.

And there's another kind of illusion which is very powerful. Take
music, divide it into little segments and fill every other segment with
noise. We perceive that the music is continuous.. the book says that
you actually think you hear a continuous rhythm, or if the music has
glissandos you hear them uninterrupted.

I'm not going to try to relate this example directly to the debate
about blind tests, but I think there are some concepts about perception
lurking here.

One concept is "labelling". Given some sensory input, do you recognize
parts of it with concepts that can label it? The visual scene with
random shapes has no label-able constructs in it. However, in the same
scene with the blob of ink, the letters jump out at you. I find that I
can now picture that scene in my memory, while I can't picture the
random shapes at all.

In the auditory realm, we could hear a signal and regard it as a
complex, unrecognizable sound. Or we could hear a signal and perceive
that it is a spoken English sentence.

Labelling relates to memory. You have better long-term recall of
something that you have labelled. For example, there's an experiment
in which memory for pitches is tested. People without absolute pitch
cannot remember a pitch for more than one minute. People *with*
perfect pitch can, and their ability to recall doesn't show a typical
"fading" curve. It is presumed that they label their perception of the
pitch and remember the label.

In my blind tests, I tried to notice concepts that could be labelled.
For example, I might note "the bass comes to my attention." Most
people, when they first try to hear small differences in sound, have no
labels for the experience. While I am not going to make a direct
conclusion about blind testing, I will note that the label-ability of a
phenomenon will affect the long-term recall of it.

-Mike