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Thomas Stockham

February 3, 2004

A public radio commentary

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