Mind Stretchers
"Dick Pierce" wrote in message
...
Mr. Eickmeier, you have a lonn history of taking a term,
redefining it for the purposes of some agenda, without
letting anyone else know about your surreptitious redefinition,
and then proceeding to argue from that point.
Mr. Pierce, what a treat! Thank you for taking the time to share your
extensive knowledge.
For the record, "surround sound" was NEVER designed as a means
of recreating the original sound field. Things like 5.1 surround
and the like were developed as effects systems used in conjunction
with video and the like. James Jophnston has elsewhere described
how completely innappropriate surrtound-sound systems are for
recreating sound fields. Perhaps you might want to research
the subject before you hold forth on it.
Hey, what a great idea! But, indeed, I have been reading voraciously about
all this for over 30 years now! But I didn't stumble across a statement like
that - do you have any references or quotes to help us out here?.
As to the "definition" of stereo sound, you may well like to
redefinf it however you like, but you should note that there's
an 80 jump on your claim to the definition, and should you
disagree, you might want to take it up with the kind folks
at Bell Labs.
Gosh, it sure seems like you know something there that I don't - but. I have
quoted the research from Bell Labs in my various papers and writings. My
favorite reference is William B. Snow's 1953 paper
that is republished in the AES Anthology of Stereophonic Techniques. In it,
he defines all of the auditory perspective systems.
Yes, among other things, you have a LOT of reading up to
do, not the least of which is on fundamental definitions.
Thanks for the tip. So let me read to you for a minute:
From R. Vermeulen's paper on Stereo Reverberation (JAES, vol. 6, no. 2, pp.
124 - 130, 1958 April):
NECESSITY FOR AUGMENTED REVERBERATION
It is true that by suitable positioning of the microphone we can pick up
reverberation sound from the hall and reproduce the plolongation of the
sound. But here again, we are apt to make the same mistake in that we
reproduce only one and - of course - the only measurable characteristic of
the sound field, viz, the reverberation time, but neglect its spatial
distribution. The loudspeakers of a stereophonic set can never reproduce the
sound field in the concert hall with any accuracy in the home; how indeed
could they do so with only the data from two microphones at their disposal?
Neither can they deliver to the listener's ears exact copies of the
instantaneous sound pressure at the place of the microphones, if only
because the listeners are free to move their heads and are sitting at
different places. The loudspeakers can only produce a quite different sound
field, which will nevertheless give an impression that resembles the
original in certain respects. But not in all rexpects, beause they are only
capable of simulating sound sources in the space between them. Thus
stereophony can only widen the "hole in the wall of the concert hall" to a
"large window" but it cannot give the listener the impression that he is
present in the auditorium. It cannot imitate the sound reflected from all
sides by the ceiling and the walls. This does not matter as long as the
reproduction takes place in the concert hall itself where the ceiling and
the walls are present to produce reverberated sound with the desired
properties. In a living room, however, the absence of enough reverberated
sound or at least its different character places the listener in the positon
of an outsider."
He goes on to describe how to simulate the reverberant field by means of a
distribution of loudspeakers.
Permit me one more quote, this time from Blauert (the well-known Spatial
Hearing book, p 282) in describing the two basic approaches to transmitting
a spatial impression across a distance of space and time:
"In principle two approaches to solving this problem are possible. One
consists of generating a sound field in the playback room that corresponds
largely to that in the recording room. Such an electroacoustically generated
sound field is called a 'synthetic sound field.' The second approach
proceeds from the assumption that an optimal acoustical reproduction is
attained if the subject's ear input signals are collected, transmitted, and
reproduced. Processes employing this technique are called binaural or 'head
related' since a head, usually a dummy head, is used in collecting the ear
input signals."
His "synthetic sound field" is a large collection of microphones leading to
a similar number of speakers around the subject in an anechoic environment,
in an attempt to duplicate the original field as much as possible, or
necessary. Surround sound in the home theater system is a simplification of
this approach, which most of us realize by common sense.
You might want to do some more reading on this subject, starting
with those two sources. It is possible that you could use some reinforcement
in acoustics and psychoacoustics.
Gary Eickmeier
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