Wednesday, February 13, 2008

Grammy For Math ... At The Wire

50TH ANNUAL GRAMMY® AWARDS 3-D Logo - Image Credit:

Grammy For Math ... At The Wire

Math algorithms aid our lives in many ways. Here at Symblogogy, we have highlighted the use of math and the reading of symbols with regards to:

** Barcodes for retail transactions and item tracking identification
** Two-dimensional symbologies that are able to deliver small databases that can be attached to an item and decoded on-the-spot with out the need to refer to a database.
** Cameraphone 2-D codes used to acquire additional information through a connection with internet webpages (PWC/PWH - Physical World Connection/Physical World Hyperlink). Applications include having the code appear in print advertisements so that one could scan (take a picture of the code) and read from their display.
** Three-dimensional codes where a 2-D code includes the element of color discernment. This type of symbology was invented to allow one to transport even more information to be decoded on-the-spot. Information is decoded through a math algorithm and delivers enough information to display and play a twenty (20) second low resolution video … right there, in the phone … without having to reach out to a website or internet database.

Just this last weekend, the use of math algorithms were recognized in a big way. Math was able to retrieve sound information that was recorded on an outdated and almost unsupported recording technology known as magnetic wire sound recording.

Magnetone Model BK-303 portable wire recorder. Example of a typical portable magnetic wire recording machine. Image Credit: University of San Diego/Courtesy of The Brush Development Company

This excerpted from Science News Online -

The Grammy in Mathematics
Mathematician nominated for award for restoring the only known recording of a live Woody Guthrie performance
Julie J. Rehmeyer – Science News Online - Feb. 9, 2008

Shortly after September 11, 2001, a small, heavy package wrapped in brown paper arrived in the mail at the Woody Guthrie Archives in New York City. Inside was a mess of wires.

Guthrie's daughter Nora eventually figured out that the suspicious package wasn't a bomb, but rather a recording of her father on a device that predated magnetic tape. After a year of searching, she managed to track down someone with the equipment to play it.

What she finally heard was a bootleg recording of her father singing a live performance in 1949. It was the first time she had ever heard him perform in front of a live audience. He had developed Huntington's chorea and stopped performing when she was a child, and she thought he had never been recorded live.

So she was determined to preserve the recording. For the first step, she and a team of engineers transferred it into digital format. It was a hair-raising experience. "The wire was really flimsy," says Jamie Howarth, a sound engineer on the job. "It was frustratingly, maddeningly fragile." It snapped over and over, and with every snap, a moment of the recording was lost. And when it didn't snap, it kinked and snarled.

After a 36-hour session, Guthrie and the engineers listened to the recording they produced. The pitch rose and fell independent of Guthrie's singing. They could hear him telling long stories, but only every few words were intelligible. The wire had stretched in places, slowing the recording down. The kinks produced moments of silence.

Howarth is the head of a company that specializes in restoring old analog recordings. If a tape slows down for any reason either during recording or playback, it lowers the pitch and stretches the sound out longer. If it speeds up, the pitch goes higher and the sound goes faster. Howarth had found that slight speed variations occur even in modern recording equipment, creating slight distortions that sound like "wow-wow" or a flutter.

Fortunately, math can help. Howarth had developed algorithms to correct these recordings.
When a recording is made, this background rhythm is even. But when it's played back, it speeds up and slows down in perfect timing with the errors in the recording. That allows Howarth to adjust the timing of the recording to make it much more similar to the original sound.
The Guthrie recording was such a mess that it forced him to develop new techniques. He turned to Kevin Short, a mathematician at the University of New Hampshire who had done work on signal processing for sound compression.

The team discovered the many ways that wire makes a lousy material for sound recording. One problem is that wire's round. When the wire kinked, it would twist out of position and the head would no longer be reading the proper side of the wire. The machine still read the low and medium frequencies, but the very high frequency sounds dropped out—including the signal Howarth used as his foot-beat.

Short developed techniques to interpolate the missing information. "We could actually pick up a hum from the Con Edison power supplies," Short says. "It's a pretty nasty noise." Because that hum was lower frequency, it remained even in the twisted sections. Short also brought in more sophisticated techniques to shift the pitches once the algorithm had identified what needed to be done.

"When it was done, we were all just awed by this recording," Howarth says. "It was miraculous." Despite all the difficulties in the process, the wire recording was in many ways surprisingly good. "It sounds really, really, really good for its time," he says.

To test his algorithms, Howarth whapped a pencil eraser against the transport of a tape player during the recording of a single, steady tone, disrupting its even motion. The top sonogram shows the recorded pitch varying wildly with the disruption. He then corrected the recording using his algorithms and removed the distortion entirely, producing the bottom sonogram. Image Credit: J. Howarth / Plangent Processes

Sound File: Guthrie Clip 1—Before processing

Sound File: Guthrie Clip 2—After processing

To hear a sample of the recording, before and after processing, click on the sound file links above.
[Audio clips courtesy Woody Guthrie Publications, Inc. Copyright © 2007, Woody Guthrie Publications, Inc. Used by permission]

The restored recording was released last September and was almost immediately nominated for a Grammy. The award ceremony will be broadcast Feb. 10.
Reference Here>

And the winner is ... Image Credit:

The Grammy for Best Historical Album (category 91) was awarded to “The Live Wire” - Woody Guthrie In Performance 1949:

Category 91

Best Historical Album (winner highlighted in orange)

** Actionable Offenses: Indecent Phonograph Recordings From The 1890sDavid Giovannoni, Meagan Hennessey & Richard Martin, compilation producers; Richard Martin, mastering engineer (Various Artists)[Archeophone Records]

** Forever Changing: The Golden Age Of Elektra Records 1963-1973 (Deluxe Edition)Stuart Batsford, Mick Houghton & Phil Smee, compilation producers; Dan Hersch & Bill Inglot, mastering engineers (Various Artists)[Rhino]

** The Live Wire - Woody Guthrie In Performance 1949Nora Guthrie & Jorge Arévalo Mateus, compilation producers; Jamie Howarth, Steve Rosenthal, Warren Russell-Smith & Dr. Kevin Short, mastering engineers (Woody Guthrie)[Woody Guthrie Publications]

** Love Is The Song We Sing: San Francisco Nuggets 1965-1970Alec Palao, compilation producer; Dan Hersch, Bill Inglot & Dave Schultz, mastering engineers (Various Artists)[Rhino]

** People Take Warning! Murder Ballads & Disaster Songs 1913-1938Christopher King & Henry "Hank" Sapoznik, compilation producers; Christopher King & Robert Vosgien, mastering engineers (Various Artists)[Tompkins Square]
Reference Here (field 27)>>

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