AES Convention Report (LONG)
David Rick
I just returned from the Audio Engineering Society convention in
New York, and thought I would jot down my impressions for the net.
Interesting papers:
There were many, including an invited lecture by Manfred R. Schoeder
on chaotic systems and applications in audio. His new book on the
subject is due out in short order. I'll buy it; this man in a big
hero of mine...
A large assortment of other luminaries in room acoustics, including
Wolfgang Ahnert, H. Kuttruff (who told me that the third edition of
his excellent book will be published shortly), and many others presented
papers and demonstrations on computer and scale-model simulation of
room and concert hall acoustics. The new buzzword is "auralization,"
which is meant to suggest the auditory analog of "visualization," by
which means a proposed hall design can be simulated and, through the
wonders of DSP, "auditioned" before it is actually built. Several
researchers brought demo tapes. The scale model simulations sounded
horrible. Some of the computer ones definitely sounded "plausible";
it remains to be proven which of them are also accurate, and how good
(i.e. how expensive) the modeling really has to be, in order to be a
useful design tool.
BTW, the design software I am aware of at present is:
Umbulus. Older generation, proprietary. Developed by Tom McCarthy
at NorthStar Sound (Mpls) and D. Michael Shields at Ampria R&D (St. Paul).
Sound reinforcement oriented.
P.H.D. Older generation, developed by John Proh. I don't know much about
this package.
CADP2. "Complex Array Design Program," by JBL. Sound reinforcement oriented,
as you might guess. Very pretty color mapping of horn coverage, direct/rev-
erberent sound ratio, etc. JBL has very high resolution polar data for
their products; other manufacturers are trying to catch up.
Modeler, v. 4.0. Mac-based package from Bose, written by staff engineers
Tom Birkle and Ken Jacob. Clean user interface, very nice graphical
displays, including color maps similar to the JBL package. Reflections
are modeled to third-order at most. A statistical "tail" is added to
facilitate direct/reflected energy ratio calculations. I particularly
liked the ability to click on a particular reflection in the time series,
and have the reflection path pop up on a view of the room.
EASE. Developed in Germany by Dr.s Ahnert and Feistel, and distributed
in the U.S. by Renkus-Heinz. Claims "highest accuracy simulations
available." Can handle up to 3000 reflections. This takes a while!
Nice horn-mouth-view of hall for array aiming. Review I read says the
user interface is a bit clunky, but improving. Companion package and
board will convolve short audio samples with the hall's impulse response
for audition.
AcoustaCADD. I know nothing about this.
CATT-Acoustic, v. 3.0. Developed by Bengt-Inge Dalenback, a doctoral
candidate at Chalmers University in Gothenburg, Sweden. Oriented more
towards room/hall acoustics than sound system design, it relies on typed
files to specify the room, but allows variables in the specification
so you can rapidly alter dimensions, etc. Uses a highly optimized
implementation of the "image method" to speed initial simulation, and
allow substitution of new surface treatments without incurring long
recalculation times. "You ask very good questions," the author said
upon meeting me in the hallway on the day after I heard him present his
paper, and proceeded to give me many details about his algorithms and
modeling philosophy.
CANVAS. Written by consultant Gerald I. Forstater, this program uses
room-average statistics, and does nothing that one can't do with a
Lotus spreadsheet.
Back to interesting papers:
Stanley P. Lipshitz, et. al., of the University of Waterloo,
presented a paper which reviewed optimal dither for A/D converters.
Several different researchers have discovered that the dither should
have a triangular PDF, but some, like Tom Stockham, did not publish
their results for competative reasons.
John Monforte and Ken Pohlman, from the University of Miami, examined
claims of degradation in digital copying by subtacting the later digital
data from the original, and playing the "residue" file at high volume
level. The result was null, but certain digital reconstruction methods
like 'No-Noise' produce more interesting residue files.
Author-consultant John Eargle, and Richard Greiner of the University
of Wisconsin gave a well-attended tutorial on musical instrument acoustics.
Later, Greiner presented the results of a large double-blind listening
study which showed that listeners could perceive absolute polarity in
very simple signals, but that they fared little better than chance in
telling the difference in more complex musical examples.
Michael Gerzon presented too many papers to cover here, and received the
Society's gold medal for his work on Ambiasonics. He also collared me
in the hallway and talked nonstop for an hour and a half, causing me
to miss lunch.
Net.personality Max Hauser, of Signetics, presented a tutorial paper
entitled "Analog-Digital Equivalence." I will risk Max's ire by
summarizing his talk as follows: Analog and digital representations
have much the same kinds of problems, when viewed in an information-
theoretic context.
Former net.personality David Moran gave a paper in which he compared
measurements and spreadsheet calculations of the "Allison effect"
which produces big dips in the upper bass or lower midrange of speakers
when mounted on stands in real rooms.
Five Japanese researchers presented the results of a well-controlled
psychoacoustic study that showed that listeners perceive differences
between music signals in which 20 kHz to 100 kHz (yes!) frequency
content is present or missing. The difference can be quantified as
changes in the listeners' EEGs, but are missed in traditional A/B
testing because the brain patterns "hang on" for a long time and
confuse the results when "A" and "B" alternate quickly. This is
a hell of a fine piece of research, and the authors received many
appreciative comments from the assembled audience.
Hot topic: Low bit-rate audio coding.
There were several papers and some auditory demonstrations of systems
that use psychoacoustic masking models to allow coding of "CD-quality"
audio at bit rates of 4 bits per sample and lower. The best-known
example of such a system is Philips' Digital Compact Cassette, details
of which were presented in four back-to-back papers.
Hot products:
In between papers, I walked my legs off trying to get through four
floors of exhibits. Here are some I found especially interesting.
Korg has a complete 8-track digital workstation for sound-for-video
and audio "sweetening" applications for $35,000. This is a big
price breakthrough. The demo involved snipping out an explosion
sound from a video soundtrack (whilst watching the video in sync)
and replacing it with a sample of Buggs Bunny saying "what's up
Doc?" The system looked remarkably straightforward to use.
Try as I might, I could not get in to see the Alesis ADAT, which
puts 8 tracks of digital on a VHS cassette for $4000, and is
cascadable to 128 tracks. Too bad -- I want something like this
badly and their preliminary data sheet has no specs.
A vendor whose name I've lost (but will scrounge up on request) had
a "poor man's TEF system" for $995. It is a PC plug-in card, and
is the cheapest way I've seen of doing "semi-anechoic" (i.e. gated)
measurements on speakers and the like. The competition is Techron's
TEF and DRA's MLSSA, which cost 3 to 6x as much.
Sabine showed both versions of thier FBX "feedback exterminator" which
is a box that automatically moves narrow-band filters around to stop
feedback in sound reinforcement systems. The booth staff at first
didn't want to bother with me, but when I said "It strikes me that this
box would do no good for a feedback mode that results from a single
discrete reflection, since the filter phase shift would just move
the mode to a different frequency," they steered me to an R&D engineer
who happily showed me the internals of the "professional version," still
under development. It uses a DSP rather than analog filters, and
can find feedback even when it is well below the music signal. Of course,
it still has the limitation described above, but could be quite useful
in more diffuse situations.
Speaking of feedback, Lexicon demonstrated their reverberation enhancement
technology for concert halls, etc. Past attempts at this sort of thing
have been plagued with feedback problems; Lexicon reprograms their
reverberation hardware continuously so that the virtual room modes go
away and are replaced by different ones before ringing has a chance to
develop. Not only is this a useful technology for implementing variable
hall acoustics, it also has a fascinating application in sound reinforcement:
one reinforces with diffuse rather than coherent sound. As a result, the
effective "critical distance" gets much smaller, and one can actually
point the microphone directly at a loudspeaker, or put it very far from
the performer/talker, without encountering feedback!
Emu had their new keyboard available for tryout, which I did. The action
seemed very nice, at least to this non-keyboardist, and it felt and sounded
a _lot_ like a real piano. Some of the other samples were impressive as well,
but they mostly don't fit into the kind of music that I play.
Hyperception's Hypersignal software cropped up in several booths, including
their own. The era of the point-and-click FFT has arrived. The software
also allows "connect-the-icon" programming of signal processing algorithms.
There were lots of loudspeakers. There were _lots_ of loudspeakers.
There were TOO DAMNED MANY loudspeakers. Some were being demoed in
suites upstairs. How one can learn anything in such acoustics is a
mystery to me. One could, however, go deaf.
Irreverently submitted,
David L. Rick
dr...@hplvdo.lvld.hp.com
Disclaimer: These are my opinions, not my employer's, and they are
just that, OPINIONS, so take your attorney and stick him inside a
working Community bass horn until he quiets down or it does!
Kurt Strain
> Five Japanese researchers presented the results of a well-controlled
> psychoacoustic study that showed that listeners perceive differences
> between music signals in which 20 kHz to 100 kHz (yes!) frequency
> content is present or missing. The difference can be quantified as
> changes in the listeners' EEGs, but are missed in traditional A/B
> testing because the brain patterns "hang on" for a long time and
> confuse the results when "A" and "B" alternate quickly. This is
> a hell of a fine piece of research, and the authors received many
> appreciative comments from the assembled audience.
Let's see here. What's this? A test that shows the need for frequencies
beyond 20 KHz, long theorized by a few scientists and audiophiles but
denied heavily by experts of rec.audio. I do believe I can remember the
words to such a statement: "Lies, lies, lies!" Another one was: "Hey, Kurt
a real-world-knowledgeable person said that there is no use for frequencies
above 20 KHz." Also, it says the differences were missed in traditional
A/B testing. Another statement about that like "Kurt, maybe you should
consider stopping your misinformation if you want me to stop harrassing you."
That came from the same guy who demands SOME consideration from the net.
I hope I'm not sinking this group to a new low Bill by telling you my
feelings have been trashed and my rights to express myself have usually
and often been stomped on because people didn't agree with it. Tough being
in the minority and want to fully express yourself. You get 20 guys against
at once. How can you deal with that? I don't do it well. I'm sure this will
go down as yet another "lie" for some of you, so try to hold down any epithets
you may think of using against these fine Japanese researchers. And for
the one idiot who wrote me claiming I might be a racist: The word Jap is
derogatory against people of Japanese citizenship, or Japanese origin, not
against the entire Asian continent or the oriental race. It is a WWII term
used against a nation, not a race. You can have white Japanese believe it
or not, and one of these reseachers might have been one. So get educated
yourself. And besides, the original poster of that article apologized from
the outset on the string for the use of the term. Standard rec.audio
etiquette is to never say anything controversial. This is beyond the bounds
arleady, huh? Oh, well, it's perfectly okay to humiliate the person with
the new idea to the point of destroying his mind as long as you don't say
any epithets, right? I just want to be perfectly clear before I try to re-join
the rec.audio thought control police.
So when are they going to make a better CD format instead of a worse one?
Richard Wallingford
> Five Japanese researchers presented the results of a well-controlled
> psychoacoustic study that showed that listeners perceive differences
> between music signals in which 20 kHz to 100 kHz (yes!) frequency
> content is present or missing. The difference can be quantified as
> changes in the listeners' EEGs, but are missed in traditional A/B
> testing because the brain patterns "hang on" for a long time and
> confuse the results when "A" and "B" alternate quickly. This is
> a hell of a fine piece of research, and the authors received many
> appreciative comments from the assembled audience.
Let me get this straight. The listeners couldn't *hear* the
differences but they had an effect on their EEGs?????
I'm sorry, but I wouldn't pay for extra bandwidth beacuse
of its effect on my EEG. I would have to hear the improvement.
--
Dick
Len Moskowitz
> Let me get this straight. The listeners couldn't *hear* the
> differences but they had an effect on their EEGs?????
>
> I'm sorry, but I wouldn't pay for extra bandwidth beacuse
> of its effect on my EEG. I would have to hear the improvement.
What if the EEG effect was indicative of the music's emotional effect?
Len Moskowitz
WATERS,CLYDE GORDON
>In rec.audio, dr...@hplvec.LVLD.HP.COM (David Rick) writes:
>> psychoacoustic study that showed that listeners perceive differences
>> between music signals in which 20 kHz to 100 kHz (yes!) frequency
>> content is present or missing. The difference can be quantified as
>> changes in the listeners' EEGs, but are missed in traditional A/B
>
>differences but they had an effect on their EEGs?????
>
>I'm sorry, but I wouldn't pay for extra bandwidth beacuse
>of its effect on my EEG. I would have to hear the improvement.
Wait a minute... Like, where is any other possible input sources? They
surely didn't feel (unless it was louder than 120 dB), see, taste or
smell it!!!
I think that the ear could safely be labelled the receptor here. Hmmmmm,
however, maybe something for the next battery of tests to determine
concretely.....
Reckon anyone could suggest this to the Japanese gentlemen ???
Just a wierd idea, but no wierder than some tests I've seen done
in the name of "audio science"...
rambling on....
Regards,
Gordon.
--
WATERS,CLYDE GORDON-Georgia Institute of Technology Atlanta Ga 30332
******<LANGUAGE IS A VIRUS! - Laurie Anderson-Home of the Brave>*******
uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!gt0869a
Internet: gt0...@prism.gatech.edu
Richard Wallingford
The emotional effect would be perceptable (unless it put me in
a good or bad mood for an otherwise unexplained reason).
I can picture it: System "A" made me mad, system "B" made me
laugh, system "C" made me cry ......
--
Dick
Shailendra Save
##>
##>
##>> Five Japanese researchers presented the results of a well-controlled
##>> psychoacoustic study that showed that listeners perceive differences
##>> between music signals in which 20 kHz to 100 kHz (yes!) frequency
##>> content is present or missing. The difference can be quantified as
##>> changes in the listeners' EEGs, but are missed in traditional A/B
##>> testing because the brain patterns "hang on" for a long time and
##>> confuse the results when "A" and "B" alternate quickly. This is
##>> a hell of a fine piece of research, and the authors received many
##>> appreciative comments from the assembled audience.
##>
##>Let me get this straight. The listeners couldn't *hear* the
##>differences but they had an effect on their EEGs?????
##>
##>I'm sorry, but I wouldn't pay for extra bandwidth beacuse
##>of its effect on my EEG. I would have to hear the improvement.
##>
##>--
##>Dick
What he is trying to say, is that the music is not "heard" but is
"felt". Same thing for frequencies below 20Hz. You can feel the rumble,
but not hear it. It makes a difference.
Shailendra
ss...@caen.engin.umich.edu
ole!ss...@sumax.seattleu.edu
Kurt Strain
> Let me get this straight. The listeners couldn't *hear* the
> differences but they had an effect on their EEGs?????
>
> I'm sorry, but I wouldn't pay for extra bandwidth beacuse
> of its effect on my EEG. I would have to hear the improvement.
> --
> Dick
Dick could very well be right. Will the debate never end?
Kurt Strain
> What if the EEG effect was indicative of the music's emotional effect?
You know that's it! On CD, the music just doesn't get you in your heart.
Bill Case
>
> Let me get this straight. The listeners couldn't *hear* the
> differences but they had an effect on their EEGs?????
>
> I'm sorry, but I wouldn't pay for extra bandwidth beacuse
> of its effect on my EEG. I would have to hear the improvement.
I disagree. IMHO, I've always felt that the measurement of the musical
experience was how much parts of your brain "lit up" with pleasure.
If certain "inaudible" frequencies changes the brain response, then
it's valid input. In fact, on a slightly different tangent, if
you read "Zen and the Art of Motorcycle Maintenance, you find
the suggestion that true quality is sensed at the cutting edge of
experience, and that certain "goodness" or "badness" is just known
before the experience is converted into objective and subjective
measurements. Perhaps (note, I did say "Perhaps") the EEG is picking
up the brain experiencing the goodness or badness of the experience,
and a lot of double-blind tests fail to reflect this because:
a) they are asking that part of the brain to give a verbal
rating of experience, and it can't do it.
b) regardless of how fast the A/B switch is thrown, you are
asking the testee to
1) move the experience into the objective/subjective sphere
2) rate experiences which are no longer current. Perhaps
the brain centers seen by the EEG collapse as fast as
a lightbulb (oooo, or a quantum wave :-) when you cut of
the juice (experience).
The A/B tests depend on either the presense of vestiges of experience,(i.e.,
the aftertaste is still there to rate), or the assumption that the brain
segments that "light up" can verbalize the experience. But then, so does
Stereophile and ABsound. Hmmm.
However, I haven't read all the material, so I should keep my amateurish
mouth shut!
Excuse me while I reach for another mushroom and place "William Shatner reads
from Carlos Castaneda" on my Zen..uh Linn.
Bill "still likes the Troggs" Case
...uunet!ingr!b11!casey!case (UUCP)
ingr!b11!casey!ca...@uunet.uu.net (ARPANET)
ca...@ingr.com (Internet)
Griff Smith
| >> Five Japanese researchers presented the results of a well-controlled
|
| below 20Hz. You can feel the rumble, but not hear it. It makes a difference.
|
| Shailendra
| ss...@caen.engin.umich.edu
| ole!ss...@sumax.seattleu.edu
Perhaps what they're measuring is the cry of brain cells as they're
turned to mush by ultrasonics. Given how weak these signals are in
real music, I'm willing to forgo this experience.
--
Griff Smith AT&T (Bell Laboratories), Murray Hill
Phone: 1-908-582-7736
UUCP: {most AT&T sites}!ulysses!ggs
Internet: g...@ulysses.att.com
jj, like it or not
>In rec.audio, dr...@hplvec.LVLD.HP.COM (David Rick) writes:
>
>
>> Five Japanese researchers presented the results of a well-controlled
>> psychoacoustic study that showed that listeners perceive differences
>> between music signals in which 20 kHz to 100 kHz (yes!) frequency
>> content is present or missing. The difference can be quantified as
>> changes in the listeners' EEGs, but are missed in traditional A/B
>> testing because the brain patterns "hang on" for a long time and
>> confuse the results when "A" and "B" alternate quickly. This is
>> a hell of a fine piece of research, and the authors received many
>> appreciative comments from the assembled audience.
you may be sure. What's reported is not an impossibility,
given that outer hair cells seem (under some studies and
circumstances) to have suppressive effects, and the structure
of the cochlea could permit some excitation above the usual
"audio" frequencies.
On the other hand, there have been several interesting studies
done in the past regarding bandwidth that do no have the
'A/B' problem alluded to, that express other results. It will
take a careful reading of several reports to see what's to
be learned.
One major concern I have is the question of transducer accuracy
and distortion. I hope to find it addressed in the preprint.
It's not a simple problem. Neither is the isolation problem
involved in measuring brain waves in the presence of some
kinds of transducers.
>Also, it says the differences were missed in traditional
>A/B testing. Another statement about that like "Kurt, maybe you should
>consider stopping your misinformation if you want me to stop harrassing you."
>That came from the same guy who demands SOME consideration from the net.
So, what's your point? You repeatedly provide misinformation to
the net regarding what "jj said" as well as providing deliberately
misleading and provocative statements about other posters. That
is clearly grounds for objecting to your behavior. This objection
is unrelated to whatever audio opinions you may hold. As an
example, I do NOT recall saying "... stop HARRASSING...".
That's completely aside from your opinions on audio, which
are NOT what I've objected to in the past. I don't agree
with your positions on audio. I OJBECT to being slandered,
to have words put in my mouth for the purpose of defaming me,
and to be held up as the prototypical anti-progressive nazi.
I also object to the word "Jap". It's no better or worse
than any number of other racial epithets. I think it's indicative
of the problem that you've opted to argue for racism merely because
you dislike a poster opposed to it. Perhaps you should rethink
your position?
--
An alarm it *Copyright alice!jj 1991, all rights reserved, except transmission
did sound in the *by USENET and like free facilities granted. Said permission is
still of the night,an*granted only for complete copies that include this notice.
alarm that for years... *Use on pay-for-read services specifically disallowed.
andrew.charles
>IMHO, I've always felt that the measurement of the musical
>experience was how much parts of your brain "lit up" with pleasure.
>If certain "inaudible" frequencies changes the brain response, then
>it's valid input.
A lot of postings on this topic seem to be assuming:
a) The changes in EEG changed the experience of the sound.
b) The change was related to the content of the sound
(not, perhaps, just the fact that sounds in > 20K frequency
were present).
c) The experience changed for the better.
Based only on the post which started this thread, none of these assumptions
are justified.
My impression is that this study has just opened the door and more work
will follow. Personally, I hope they try to answer (a)-(c). (b) seems
the easiest to test.
Andrew Charles
ac...@ihlpe.att.com
Kurt Strain
>Also, it says the differences were missed in traditional
>A/B testing. Another statement about that like "Kurt, maybe you should
>consider stopping your misinformation if you want me to stop harrassing you."
>That came from the same guy who demands SOME consideration from the net.
> So, what's your point? You repeatedly provide misinformation to
> the net regarding what "jj said" as well as providing deliberately
> misleading and provocative statements about other posters. That
> is clearly grounds for objecting to your behavior. This objection
> is unrelated to whatever audio opinions you may hold. As an
> example, I do NOT recall saying "... stop HARRASSING...".
>
> That's completely aside from your opinions on audio, which
> are NOT what I've objected to in the past. I don't agree
> with your positions on audio. I OJBECT to being slandered,
> to have words put in my mouth for the purpose of defaming me,
> and to be held up as the prototypical anti-progressive nazi.
>
Your letter to me about how you will continue writing me negative letters
until I stop my misinformation came after I had done nothing other than
post published articles. But I also protested against Bob Meyers remark made
earlier about my interconnects as "maybe you made a bad move and won't
admit it to yourself." I object to being slandered and this man with
only initials does his fair share. He just doesn't understand what he
reads sometimes and gets trigger happy. He thinks he's upholding high
standards of professionalism by policing every profanity and unkind
remark directed at no one. What he really is to me is my first
encounter to flaming on this net, unprovoked if you ask me, and where
he defamed my observations as "LIES." Then I wrote further on and he
objected to my "omniscient prose", so to speak. There is nothing he
will not criticise and you can bet I learned how to flame and act like
a tyrant through his example. After all, he never gave in an inch, why
should I? I know he can't change his way of objecting to every opinion
like it's an assault on his honor, so I would request that he no longer
respond to my postings and I will not do so to his. And if you were
as sensitive and courteous as you say you are, you would not refer to
rec.audio after I've been on it as "Nutnoise". Read on:
The only reason I went "off the deep end" was because of this man and a few
others who "demanded" I come up with the reasons for hearing the things I did,
which everyone flat out denied. I couldn't just let it die, I felt I was right
and I had to understand it, because I hadn't completely. I was theorizing
as I posted along, losing much sleep. I was obsessed with the concepts I
was learning, and recalled many articles I never believed were true. I could
not sleep, my mind was racing. In fact, I lost about 2 weeks of sleep
averaging about 1 hour sleep per day. Congratulations, you were witness to a
manic episode those of you who were reading this weirdness. You think I'd
be embarrassed about what I wrote, I know exactly what I wrote, I had about
20 posted articles committed to memory at one time. Too late to be embarrassed.
One person posted that I went off to have my mind detuned at the Betty Ford
Clinic. He was not too far off, I was hospitalized for manic-depression, an
illness that affects most the great artists (like me :-)) and occurs
by heredity in persons usually in their late 20's (I was 29). It was said
that Rossini wrote The Barber of Seville in a manic rage that allowed him
to write the whole thing in less time than it would for a sane person to just
copy it. To learn more about this, there's the excellent book entitled
"Moodswing" by Dr. Fieve.
Since this time I have had a degree of moodswing,
but I take drugs to control it. Some of the side effects I have had have been
TMJ causing tinnitus in the ears, a stress disorder. That hasn't gone away
fully but is improved. Naturally, this TMJ greatly sensitized me to the
pain of CD. It's very grainy and irritating. Anyway, it's been no picnic
for me trying to enjoy music and it's pretty ironic that it all happened
after I just got my whole expensive system. It isn't just ironic, it's
been downright depressing (at times :-)). But my wife loves the system,
at least.
And I've held a bit of a grudge to those who sent me on through this, but
they didn't know what I was going through. I should apologize for my
rages that I really couldn't control. I should not be writing here if
I knew what was good for me.
I felt compelled to write this because I know a lot of people have wondered
what the hell happened. Usually I'd keep this personal, but better to let
them know what happened than make them wonder about me. After all, there
were a lot of witnesses out there.
You know a spooky thing happened after one of my major manic-depressive
episodes during that time. I heard Paul Harvey report on the radio that
researchers in France found that the peaceful near-death experience where
the brain relaxes is a hoax. The brain races to find truth and meaning
and this panic situation. And then they emerge having found new
and better priorities in their lives. That's similar to my experience.
Did psychologists read these notes? I do remember an input from France
by a guy trying to stop my rage at the time. Coincidence? Anyway, that
further fueled me on cycle two before I was hauled in for treatment.
Probably just my wild imagination. :-)
David Rick
Let me get this straight. The listeners couldn't *hear* the
differences but they had an effect on their EEGs?????
I'm sorry, but I wouldn't pay for extra bandwidth beacuse
of its effect on my EEG. I would have to hear the improvement.
The listeners did hear a difference in the character of the music,
and judged it to be an improvement over a) no very high overtones
b) the overtones replaced by high frequency random noise. The
music was gamalon music, BTW. It was chosen because it has much
more energy at these frequencies than other types of music.
Extrapolate with care!
David L. Rick
dr...@hplvdo.lvld.hp.com