Going Digital: The 1960s - IEEE Global History Network

60 Chapter 4 Going Digital: The 1960s
BEN GOLD: After a while we were able to test our own vocoder with our program
pitch detector. It was slow: to analyze two seconds of speech took the
computer about two minutes, 60 to 1 real time. So here is what we had to do.
We had to take the speech down to the computer, run the speech in through
the computer, run the pitch detector program, record, make our 2-track
recording, and bring it upstairs to where the vocoder was. It was pretty slow.
So we kept saying, "Wouldn't it be nice if we could program the vocoder on
the computer?" So we went back to Bell Labs, and visited Jim Kaiser. There
may have been other people there, but he's the one I remember. He said he
knew how to build certain digital filters. That was just what we needed. We
said, "My God, this is fantastic." We could actually build digital vocoders. 1
BEN GOLD: The FFT was really kind of a bombshell. That was what created
digital signal processing as a real field, because it has so many possible applications.
I still feel that the period starting with some of Kaiser's stuff, some of
our stuff, and working its way up to the divulgence of the FFT, from '63 to '67,
was when the whole thing exploded and became a real field. 2
1Ben Gold oral-history interview 15 March 1997, p. 7.
2Ben Gold oral-history interview 15 March 1997, p. 3.
permit the use of Hushaphones. 11 These rulings opened the gate to the de..
sign, manufacture, and marketing of a whole range of telephone..related
equipment, such as modems, answering machines, and office communica..
tion systems. 12
The speed at which modems could operate was limited by the distor..
tion of digital signals during transmission (since the shorter the duration of
each bit, the more easily a 0 could be mistaken for a 1 or vice versa). To
reduce distortion and thus increase the speed of modems, Robert Lucky, a
llBeranek writes [personal communication 2 January 1998]: "The Hushaphone Co. had
three of us in the hearing room in Washington: its President, whose name was Tuttle, a
young lawyer, and me as expert witness. The Bell System had an actual grandstand brought
into the courtroom to hold all their lawyers. They hired the best trial lawyer in New York to
cross...examine Tuttle and me. Three U.S. circuit court judges were assigned to hear the case
and render a decision. The case went on for several weeks. Hushaphone won the case, and
[the Bell System] was told it could not prevent this particular foreign attachment from being
used."
12Communications op. cit., p. 21.