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Thomas Stockham:
A Public Radio Commentary
by Bill Hammack
Listen using RealAudio
In early January of 2004 Thomas Stockham died. No doubt the name
is completely unknown to you, yet he had a huge impact on our
society. Due to Thomas Stockham we now have a generation that
doesn't know what a vinyl record or a turntable is. He pioneered
the science of digitally recording music, which is used to make
compact discs.
When he first considered doing this in 1962, computers were too
slow. At the time, it took nineteen minutes of computer
processing to record a single second of music. But Stockham
persisted. As he waited for computers to catch up with him, he
worked out exactly what the computers should do with the
digitally recorded music.
He studied something called "signal processing." To an electrical
engineer, a signal is any kind of stimuli to our senses - light
from a photograph, or sound from a record. Stockham focused on
ways to improve these signals - a photograph can be blurry, or a
sound might have extra noise like a hiss. An engineer calls all
of these interferences noise. Stockham developed mathematical
ways to remove this noise - to make a photograph clearer, or a
sound more distinct.
He returned to recording music when a friend asked if Stockham
could restore some antique Caruso records. Stockham jumped at the
chance.
He used his methods to record the old 78's digitally, then
removed all the pops, cracks and hisses. By 1972, he was able to
use his techniques to examine the infamous eighteen and a half
minute gap in the Watergate tapes. By this time, computers had
become fast enough that he could record live music.
His big break came when he recorded the Cleveland Symphony
Orchestra. After the session, the orchestra members crowded into
a tiny playback room to judge the results. The technician hit the
playback button and the room filled with a sound almost
unnaturally clear and sharp. The musicians could hear the squeak
of the piano pedals and the turning of sheet music. As one
musician said, "It was like being on the stage."
As Stockham recalled after this session, digital recording
"became afire then; people who had never talked to me before
started calling me on the phone and saying, why didn't you tell
us it could be this good?" Over the next few years he recorded
over five hundred records. Today, of course, digital recording
and CDs have taken over the industry.
Stockham's methods have touched all aspects of our world. His
mathematical methods are used in playing DVDs, processing Hubble
space telescope images, filtering spy photos, improving medical
images, and creating better hearing aids. But of course, it's in
the entertainment industry that he had the most impact. Small
wonder he's the only electrical engineering professor to have won
a Grammy, an Emmy, and an Academy Award.
Copyright 2004 William S. Hammack Enterprises
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