a possibility for densmore's native american recordings among others

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SCIENCE NEWS ONLINE
Week of May 29, 2004

Groovy Pictures: Extracting sound from images of old audio recordings

By Peter Weiss

Songs and words preserved on antique vinyl records and wax cylinders
become
more precious with each passing day. They also grow increasingly fragile

and are especially vulnerable to damage if played.

Now, researchers using optical-scanning equipment have made exquisitely
detailed maps of the grooves of such recordings. By simulating how a
stylus
moves along those contours, the team has reproduced the encoded sounds
with
high fidelity.

Libraries with collections of old recordings "don't want to queue up an
antique piece of material every time you want to hear it," notes
particle
physicist Carl H. Haber of Lawrence Berkeley (Calif.) Laboratory,
co-developer of the new scanning approach. Instead, those institutions
seek
to extract sound from delicate recordings and preserve it
electronically.
In that form, it can be played back repeatedly without harming the
original
and also made available on the Internet.

A few years ago, Haber heard on the radio that archivists needed ways to

nondestructively extract sound from old recordings. He and his Berkeley
lab
colleague Vitaliy A. Fadeyev, who make arrays of sensors for tracking
minute particles in powerful accelerators, realized that their own work
was
relevant. To align their arrays, they scan sensor surfaces by using a
microscope with submicrometer resolution. After hearing of the
archivists'
problem, "we thought, 'Wow! Why don't they just do it optically?'" Haber

recalls.

The scientists used their microscope to make a two-dimensional map of
the
grooves on a 78-revolutions-per-minute shellac disc of a circa 1950
recording of "Goodnight Irene." They also wrote software that calculates

the velocity with which a stylus would move in the mapped grooves. A
sound
clip from the virtual disc sounded better than the same section played
back
from the original disc with a stylus did, Haber and Fadeyev reported in
the
December 2003 Journal of the Audio Engineering Society.

Recently, the Berkeley physicists, along with other U.S. and British
researchers, showed that the approach also worked well on a 1909
wax-cylinder recording. Because wax cylinders store sound as up-and-down

undulations of the groove, rather than as side-to-side ones, as discs
do,
the team turned to three-dimensional scanning using an instrument known
as
a confocal microscope.

Haber described their work on May 25 in New York City at a meeting of
the
Acoustical Society of America.

The new mapping technique could enable archivists to retrieve recordings

from damaged or broken records and discs, comments Peter G. Alyea of the

Library of Congress in Washington, D.C., which is funding some of Haber
and
Fadeyev's work. The method could also solve the looming problem of
playing
archived recordings after old types of playback equipment become
unavailable, he adds.

Using existing equipment, the scientists would require an entire day to
scan one full wax cylinder, they estimate. One of their next tasks is to

find ways to speed the process.

� 2004 Science Service

-- -Kraig Grady
North American Embassy of Anaphoria Island
http://www.anaphoria.com
The Wandering Medicine Show
KXLU 88.9 FM WED 8-9PM PST

hi kraig,

wow, this is very cool.

-monz

--- In metatuning@yahoogroups.com, kraig grady <kraiggrady@a...>
wrote:

> --------------------------------------------------------------------
-
> SCIENCE NEWS ONLINE
> Week of May 29, 2004
>
> Groovy Pictures: Extracting sound from images of
> old audio recordings
>
> By Peter Weiss
>
> Songs and words preserved on antique vinyl records
> and wax cylinders become more precious with each passing
> day. They also grow increasingly fragile and are
> especially vulnerable to damage if played.
>
> Now, researchers using optical-scanning equipment have
> made exquisitely detailed maps of the grooves of such
> recordings. By simulating how a stylus moves along those
> contours, the team has reproduced the encoded sounds
> with high fidelity.