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Responding to Stephen Sutton's comment and Don Cox's post about advantages
and disadvantages of listening to mono-music in stereo versus mono:

Some may wonder how it could be possible in stereo to hear sound from other
than being at a speaker or between speakers. How could it be to the left or
right beyond a speaker? How could it be above, below, behind or in front of
the line between the speakers? Such a thing can happen and can be a most
entertaining experience if listening using head phones if the recording was
made using mics that are in positions that simulate the ears of a human
being. This setup may be known as stereophony sound. But even with ordinary
sound, even coming from a single speaker, sound can be thrown to appear to
come from another place. If one speaker, that throw would normally be above,
below, in front of or behind the speaker. I am not sure about or how it
could appear to come from the left or right of a single speaker. Similarly I
am puzzled by a suggestion that stereo playback of a mono recording of any
could seem to come from in front of the speaker lineup, unless that was also
experienced with the setting in mono-mode.

About throwing the position of sound? We have two ears. We can imagine
easily how we might detect sound to the left or right or centered (the
intensity reaching the ears would vary) but how can we tell if sound is in
front of us or behind us (or above or below us). Most of us realize and
experience that usually we can. How do we do that? How could that happen
with a recording? The shape of our ears produces some very small delayed
"echo" sounds to sound being received by our auditory system. Somehow our
"slow neurons" are very fast at detecting and processing such echoes to get
a clue as to the directivity of sound. For example, sound behind us has to
come around the rim of the ear but will not in a usual sense also generate a
strong delayed sound by bouncing from the cut of the ear and entering the
ear canal following a primary (initial sound) that went straight in. That
does happen when the sound enters the ear from in front of us. Even more
subtle effects must allow the analysis of our audio systems to detect that
sound is above or below us. This is all most remarkable that our hearing
systems can do this.

Anything in a sound playback system that creates echo types delays that in
some way resemble the kind of delays produced by our ears and interpreted by
our audio systems as sound positioning could produce such an effect
synthetically. It is my understanding that someone worked out a way to make
sounds move about in video games by such methods and got a patent on that. I
was listening to a recorded broadcast on television once and heard a sound
that came from the back room. I got up and went to the room to check. There
was nothing there. Curious, I replayed the portion of the program several
times. At the same moment on each playback, I heard a sound coming from the
back room. I think it was unintentional (it did not seem to relate to the
content of the program I was watching) but a noise (click or pop) that the
program had generated accidentally had produced the effect of sounding as
though it came from another place.

About listening to recordings though that are nominally mono soundtracks
(although they may have generated nominally equal left and right channels
and can technically be played as stereo), I do not see why it should matter
if the channels are combined and forced to be equal in each of the playback
speakers or if it is played back as stereo. I would expect pops, and clicks
to be equal in the speakers but I would expect the program to be equal as
well--either way. I do not understand why it would matter. I also do not
understand how it could effect where the sound seemed to come from as
regards positioning other than left and right directivity. If someone has an
answer on that I will read it with some interest.

If someone used a stylus to play back a 78 rpm record (perhaps recording
during playback) that was a stereo type stylus except that of course 78 rpm
records were mono-recordings, I imagine that one stereo channel would pick
up most of the program track but that scratches and record imperfections
might well generate a significant signal in the other channel. I would not
be surprised if such differences, provided the detected stylus outputs can
be maintained as separate signals and are not put through stereo decoding,
could be a clue to identifying the part of the recorded sound that is
accidental (a pop or click) from the part that is recorded program sound.
One channel would mainly have pops and clicks. The other channel would have
those as well as the program sound. Sound processing software that could
subtract from the one track from the other (this would be the simplest way
to exploit such an effect) with the track levels adjusted so as to minimize
hearing pops and cracks (as a first approach, that adjustment could be made
manually) could produce a resultant mix that had pops and clicks but not
program recorded sound meaningfully attenuated. This is how it appears to
me. I am interested in such matters but I have not had recent experience
with 78rpm records. I have been receiving posts to this list for only a
short time and I think this is my first post. Is such a method known and
used by those recovering recordings from 78rpm records? If it is a well
known technique, I apologize for bringing it up. If it is not known has it
been tried?

The best implementation of using the two tracks might be to couple of a high
frequency pop and click filter attenuation method with a gate determined by
the pops and clicks on the "wrong track" to signal during digital processing
when to apply the filter. Perhaps even better would be to combine an inverse
recombination of the sound from the second track to the first getting
accordingly a partial negation of the noise by gating as well and doing
attenuation on the residuals. Such gating might allow less distorting
correction of the pops and clicks (or their residuals) leaving higher
frequencies otherwise not attenuated and thereby possibly enabling a
brighter sounding recovered recording from the record.

Best regards,
Family Voices

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of Divine Art
Sent: Monday, June 09, 2003 7:02 AM
To: ARSCLIST@xxxxxxxxxxxx

While this may be true for many, I actually find the opposite, and when
listening in stereo the surface sound appears to me to be pushed forward as
well as spread, so I always listen in mono

Stephen Sutton
Divine Art Record Company
8 The Beeches, East Harlsey,
Northallerton, N. Yorks DL6 2DJ, UK
Tel +44 1609 882062
Fax: +44 1609 882091
web: www.divine-art.com
----- Original Message -----
From: "Don Cox" <doncox@xxxxxxxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxx>
Sent: Monday, June 09, 2003 11:43 AM

> However, it is easier to listen to 78s in stereo than in mono, because
> the noise is then spread across the space between the speakers, while
> the music is centred.
> That makes it easier for the brain to ignore the noise than when they
> both appear to come from the same place.
> Regards
> --
> Don Cox
> doncox@xxxxxxxxxxxxxx

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