Sonic Holography.
Richard Caloggero
**** All replies to this message should be sent to
ri...@eddie.mit.edu; I do n_t read these newsgroups. I will
summarize and post any info I receive back to the net!
----------
I am a musician/hacker with an interest in sonic imaging (sonic
holography). I am familiar with the Carver sonic hologram generator
and the basic principle used by the device. However, I recently became
aware of some experimental techniques in this area that are based, so
I've been told, on some of same principles used in modern
radarequiptment (E.G. for beam steering). Unfortunately, I forget the
jargon term used to describe the process, but its something like "phase
encoding ... :-)." Does anyone out there have any info on this?
In order to experiment with sonic holography, I would like to
obtain a computer which is suitable for real-time audio
processing. I'm sorta familiar with the Amiga, and less so with the
Mac. The Amiga, as I understand, has a special]purpose chip used
exclusively for audio signal processing, as well as A/D and D/A
hardware in the basic system box. Whatyis the speed and resolution of
the hardware? I was under the impression hhat the sample size is only
8 bits (poor resolution if ya ask me). What is thM?hhardware on the
Mac like?
As I see it, my choice of what system to buy is based on the
following. First, I need a fast processor (at least 1 mip +), I
would estimate at least 1 meg of ram (more is always better), and an
environment flexable enough to facilitate large-scale program
developement (E.G. UNIX or equivalent). Secondly, I am blind, so I
don't want hardware/software hooked to a grmphical user interface
(gimme a good old command-lin5-interpreter like CSH and I'll be
happy). From what I understand, graphical user interfaces are an
integral part of todays music type software (samplers, sequencers
etc.), as well as machines/os's like the Mac and Amiga. Does anyone
know to what extent this is true, and how I might avoid this trap?
Thanx for your help. Any information/comments will be most
apriciated. Please send all replies to me, however, for I don't read
these Newsgroups!!!
--
-- Rich (ri...@eddie.mit.edu).
The circle is open, but unbroken.
Merry meet, merry part,
and merry meet again.
Richard Sexton
impressive.
I'd be interested in whatever anybody has along these lines for
the Amiga.
Plus, there is an audio illusion I've been looking for, for quite
a while now. Basically it is an ever increasing tone.
There was a display at the Ontario Science center, ohh, 12 years or so
ago, about MC Escher, that had a ball bouncing "up" an ever increasing
staircase, with this tone, going up in pitch.
It went up in pitch for the 1/2 hour I stood there. :-)
Any clues ?
--
Richard J. Sexton
INTERNET: ric...@gryphon.CTS.COM
UUCP: {hplabs!hp-sdd, sdcsvax, ihnp4, nosc}!crash!gryphon!richard
"It's too dark to put the keys in my ignition..."
Rodney Peck
company there which was selling compact disks of "holograms". The demonstration was
really impressive. There was definitely a 3D effect especially the haircut thing where
they have scissors going around you head and they trim the back with an electric
razor. All with a standard CD player and ordinary headphones.
Rodney Peck
Rodney_Peck@rpitsmts%itsgw.rpi.edu
wil...@rocky.uucp
>ago, about MC Escher, that had a ball bouncing "up" an ever increasing
>staircase, with this tone, going up in pitch.
>
>It went up in pitch for the 1/2 hour I stood there. :-)
The effect you are looking for is produced by having two tones, one an
octave above the other. As they rise in unison, the lower tone slowly
becomes louder and the higher one becomes softer, until when they have
gone up an octave, the upper tone has completely died out and the
lower is where the upper started. Then you bring in a weak tone where
the lower one started, and repeat. The ear fools you into thinking it
is rising forever.
It might work better with more than two tones at octave intervals, but
the idea is the same.
Randy
Michael Bauers
A sound that goes up in pitch for 1/2 hour is possible. The human
ear has an amazing capacity to detect subtle changes in pitch. I have
played around a bit, and gotten tones starting a reletively high(10Khz?)
frequencies to go up in pitch for 3+ minutes. My guess is that they really
just started at a very low frequency and went up to a very high frequency
at some slow rate. If anyone has a bent for such things you can compute
the 20hz-20Khz hearing range, into delta-hz/sec, and figure out from some
source if the human ear could detect this slow of a change. On the other
hand, I might not know what the heck I am talking about.
[-----------------------------------------------------------------------]
[ Michael J. Bauers ( senior Computer Science at NDSU ) ]
[ Reply to: NU100356@NDSUVM1 or ncba...@ndsuvax.UUCP ]
[ ]
[ For God so loved the world that he gave his only son so that whoever ]
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[ Disclaimer: Frankly I do not think NDSU cares what I think, ]
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[-----------------------------------------------------------------------]
Winston Edmond
have an ever-increasing pitch is a continuously-rising tone generator. To
make one, you create many tones, more or less evenly distributed over the
entire audible frequency range. As a component tone rises to a frequency
exceeding normal hearing, it is eliminated and replaced by a tone with a
frequency that is below the normal hearing range. Since one can't hear the
tones being eliminated or added, all one is left with is the impression of
continuously-rising tones.
-WBE
John T. Nelson
> a while now. Basically it is an ever increasing tone.
>
> There was a display at the Ontario Science center, ohh, 12 years or so
> ago, about MC Escher, that had a ball bouncing "up" an ever increasing
> staircase, with this tone, going up in pitch.
>
> It went up in pitch for the 1/2 hour I stood there. :-)
>
> Any clues ?
Yup. I saw a film of this back in the 70's. The film was created at
Bell Labs. The effect is easy to reproduce. The bouncing sound
is the sum of several frequencies from 0 - 20 Khz weighted by a
gaussian distribution with the hump of the curve starting at the
lowest frequencies. Now increase the volumn on adjacent frequencies
by sliding the distribution up the scale. Your ear assumes that the
loudest frequency is the one that you heard the last time but
increased in pitched. In fact it heard all frequnecies but focused on
the most predominant (loudest).
As you slide the volumn weights towards the high frequencies the
gaussian distribution wraps around to the low end of the frequency
spectrum and the tone that your ear thought it was hearing (the high
end), fades off into the distance. By this time though it has picked
up the increasing volumn of the lower tones and is following them up
the scale.
Repeat endlessley.
All this time we were watching a film of a ball bouncing up and
Escheresque staircase and feeling like a bunch of laboratory mice.
--
John T. Nelson UUCP: sun!sundc!potomac!jtn
Advanced Decision Systems Internet: j...@potomac.ads.com
1500 Wilson Blvd #512; Arlington, VA 22209-2401 (703) 243-1611
Sine Visa Ars Nihil Est
Wade Bickel
Nic,
I tried this, on a programmable synth, and it don't work.
What you get is kind of a Barber-Pole scale, but I can
definitly recognise the roots. I tried it both starting on
the root and ending on the root, and starting on the root
and ending on the 7th, in the Major, Minor, and Minor Harmonic
Scales.
What does seem to work is simply to use at least 4 seperate
voices to gernerate independent, evenly spaced tones with
increasing frequency. When a voice reaches an upper bound
(the higher the better) set it back to something under 40hz.
Also, non-linear (increasing) functions of freq. vs time
seem to work better, but the programmablity of the synth
hindered me from better exploration of possible functions.
Both of these sounds are intersting. If I ever decide to
learn to program the audio portion of the Amiga maybe I'll
writeup a quicky demo of these effects.
Thanks,
Wade.
[Sorry for the typos - I hate line editors!]
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Richard Sexton
I got about 25 responses, about 15 accurate, 5 said "read GEB" and
5 were from people on another planet.
Thanks to all.
Peter da Silva
> There was a display at the Ontario Science center, ohh, 12 years or so
> ago, about MC Escher, that had a ball bouncing "up" an ever increasing
> staircase, with this tone, going up in pitch.
>
> It went up in pitch for the 1/2 hour I stood there. :-)
>
> Any clues ?
See Johann Sebastian Bach's "endlessly rising canon". This is a very old
illusion, based on the fact that a note sounds very much like the same note
in the next octave.
Display hack time, Leo?
--
-- Peter da Silva `-_-' ...!hoptoad!academ!uhnix1!sugar!peter
-- Disclaimer: These U aren't mere opinions... these are *values*.
os...@dewey.soe.berkeley.edu.uucp
[SUMEX]<INFO-MAC>. The program lets you go up or down forever, and includes
an animated ball rolling around an endless staircase. See pages 717-719
of _Godel, Escher, Bach: an Eternal Golden Braid_ Douglas Hofstadter, Basic
Books, New York, 1979, for a description of the sound algorithm.
--- David Phillip Oster -- This sentence is a life-like replica
Arpa: os...@dewey.soe.berkeley.edu -- of one by Douglas Hofstadter.
Uucp: {uwvax,decvax,ihnp4}!ucbvax!oster%dewey.soe.berkeley.edu
Howard A. Landman
In article <24...@gryphon.CTS.COM> ric...@gryphon.CTS.COM (Richard Sexton) writes:
>Sonic holograms ? Yes, a friend of mine has a Carver as well. Mighty
>impressive.
I borrowed one for a test listen. I found that it did make a slight difference
in the sound, but only in a very small sweet spot, and not one that was
uniformly better for all material. I was not impressed, even given the price
of $100 (used).
>Plus, there is an audio illusion I've been looking for, for quite
>a while now. Basically it is an ever increasing tone.
Piece of cake. The trick is to play sine waves at a certain note in all
octaves simultaneously. Say you start at A. Then you begin with a mixture
of A27.5, A55, A110, A220, A440, A880, A1760, A3520, A7040, A14080 and maybe
even A13.75 and A28160 if your equipment is up to it. The relative volumes
are higher in the middle and taper off toward the upper and lower registers.
Now, you increase the pitch of each wave slightly, and adjust the volumes so
that the lower tones are a little louder, and the upper tones are a little
softer, in order to keep the "center of gravity" in frequency space at the same
place. Repeat this until you have "gone up" one octave; at this point you can
delete the tone which is inaudibly high and insert a new tone an octave below
the lowest one. Guess what? You now have exactly the same signal that you
began with, and can start over. Repeat indefinitely.
--
Howard A. Landman
{oliveb,hplabs}!intelca!mipos3!cpocd2!howard
howard%cpocd2.i...@RELAY.CS.NET
"Lather. Rinse. Repeat."
Here comes the ...
>I'm posting a Macintosh version of the Shepard Tone effect to
>[SUMEX]<INFO-MAC>. The program lets you go up or down forever, and includes
>
POST IT TO THE NET!!! Please.
Some (a lot) of netters cannot (ftp) access these places.
Tanks! Joseph Judge ihnp4!cbdkc1!joe
--
Eiji A.G. Hirai
>
>See Johann Sebastian Bach's "endlessly rising canon". This is a very old
>illusion, based on the fact that a note sounds very much like the same note
>in the next octave.
More specifically, it's a piece in Bach's _Musical Offerings_. Each
of the pieces are intriguing in their own right. I'm not knowledgeable
enough in music theory but I recently perused over a book that was devoted
exclusively to anaylyzing _Musical Offerings_. Very interesting!
The piece starts on one key but after the piece nears the 'end',
it has changed to another key, and the 'end' of the piece runs smoothly into
the start of the piece, this time with the new key. The key goes on changing
until you've reached the original key, and so on and so on and so on and so...
A similar work (without the key changes but with the tail -> head
sort of loop) was done by Chopin. I can't remember what it was called,
though it was a piano piece (big surprise! - for Chopin :-)
If anyone is interested, I can dig it from my notes...
>-- Peter da Silva
-a.g. hirai
"You have just begun reading
a sentence which you have
just finished reading."
--
Eiji "A.G." Hirai @ Swarthmore College, Swarthmore PA 19081 | Tel. 215-543-9855
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Internet: bpa!swatsun!hi...@rutgers.edu | of Cnossus, Crete
Eiji A.G. Hirai
>
>See Johann Sebastian Bach's "endlessly rising canon". This is a very old
>illusion, based on the fact that a note sounds very much like the same note
>in the next octave.
More specifically, this is a piece called "Canon per Tonos" and it's
in J.S. Bach's _Musical Offering. The canon is able to repeat itself because
Bach made the 'tail' notes of the canon flow smoothly into the 'head' notes
of the canon. More importantly, the canon starts in the key of C minor
but when we near the end of the piece, it changes to the key of D minor.
So we keep on playing in the key of D minor but when we near the 'tail' again,
it changes to E, and so on and so on... Eventually, it reaches the key of
C minor, to start all over again!
Bach's _Musical Offering_ also contains other interesting pieces
too. Check out Hans Theodore David's _J.S. Bach's Musical Offering_ to
see how involved and beautiful this collection of musical delights is!
The book is devoted exclusively to the analysis of _Musical Offerings_.
Bery bery interesting...
Another piece which repeats itself is Chopin's _Mazurka in F minor_,
opus 68 posthumous (1849). You can play this piece without end, though it
doesn't have the neat key changes that "Canon per Tonos" has.
I posted a query for any pieces the net-readers know about that are
similar to these, but the response so far has been under-whelming. Oh well.
-a.g. hirai
"You have, of course, just begun
reading the sentence that you have
just finished reading."
- Peter M. Brigham
Richard Baraniuk
> sort of loop) was done by Chopin. I can't remember what it was called,
> though it was a piano piece (big surprise! - for Chopin :-)
> If anyone is interested, I can dig it from my notes...
>
> >-- Peter da Silva
I am a Chopin freak. Which is this piece?
Wade Bickel
As I remember, the original question asked for an endlessly rising
tone. These various plays on cyclic nature of the western scale achieve
a similar effect, but are not quite what was asked for.
Western music is based upon a 12 tone system. These tones are sub-
divided into sets of 7 notes which form scales (usually 7 notes). These
subsets form alternative contours. When progressing through the keys
rather than moving in one tone steps, the 5th member of a given scale
forms the next most obvious key. By doing so the scale being changed
to will contain only one note not found in its predicessor, which ex-
plains why it is the next obvious key. This is layed out clearly
for the ear in J.S. Bach's studies of the well tempered scale.
Taking this into account, it should be possible to derive any
number of always rising progressions. Of course doing so in an
artfull manner requires skill, insight, and talent. What I find
fasinating about Bach's work is the precise control of multiple
modes of the keys.
Interestingly enough, the well tempered scale is not true to
the ear. IE: if I tune my guitar by ear to a given major scale,
it will sound fine in that scale, and its cousins, but degrades
with distance from the original root. Clearly the well tempered
clavier (spelling?) is full of consistent distortions to make the
circle of 5ths fit. At least I think this is so. Any knowlegable
theory experts care to enlighten me?
Thanks,
Wade.
Stephen Smoliar
>
> As I remember, the original question asked for an endlessly rising
> tone. These various plays on cyclic nature of the western scale achieve
> a similar effect, but are not quite what was asked for.
>
I cannot remember the composer's name, although I seem to recall that he
was French. This was one of the works composed with Max Mathews' Music V
system; and, as I recall, it goes down, rather than up. Nevertheless,
the principle is applicable in either direction.
The composition was based on a timbre whose Fourier spectrum was periodic.
Thus, it could be extrapolated both above and below the limits of human
hearing. One could then gradually lower the fundamental, creating the
sense of a descending pitch. However, new partials would enter from
above as others would drop off below; and the effect was one of an
endlessly descending tone. (The dramatic effect was intended to be
that of the dropping of the "Little Boy" atomic bomb.) I have heard
this referred to as the "fencepost" effect, because it is like driving
past a long row of fenceposts with new ones always entering the visual
field and no end in sight.
Malgorzata Mikulska
>
>I am suprised that no one has cited the "Little Boy Suite" on this topic.
>I cannot remember the composer's name, although I seem to recall that he
>was French. This was one of the works composed with Max Mathews' Music V
>system; and, as I recall, it goes down, rather than up. Nevertheless,
>the principle is applicable in either direction.
>
Jean-Claude Risset, in late 1960's, Bell Labs. He used this and similar
effects in some other pieces, too (I think in "Mutations", but I don't
remember this for sure right now).
As for mentioning this piece(s), I had an impression that wasn't the
kind of "perpetuum mobile" the original poster was seeking.
Margaret Mikulska
========================
miku...@sdcsvax.ucsd.edu
sdcsvax!mikulska
=========================
Martin Taylor
--I am suprised that no one has cited the "Little Boy Suite" on this topic.
--I cannot remember the composer's name, although I seem to recall that he
--was French. This was one of the works composed with Max Mathews' Music V
--system; and, as I recall, it goes down, rather than up. Nevertheless,
--the principle is applicable in either direction.
--...the effect was one of an
--endlessly descending tone. (The dramatic effect was intended to be
--that of the dropping of the "Little Boy" atomic bomb.)
Jean-Claude Risset, published on Decca 710810 "Voice of the Computer" 1970.
(The piece is fine as music, too).
--
Martin Taylor
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Magic is just advanced technology ... so is intelligence. Before computers,
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