The Nixon Tapes Revisited
It's amazing (to me, at least) that
three decades have passed since the Watergate scandal dominated the news. One aspect of
the whole affair had an audio connection: President Nixon, it turned out, kept recordings
of meetings in the Oval Office, and these tapes were ultimately instrumental in bringing
about his downfall.
One particular tape became especially notable because some
18 minutes were missing from the middle, and since the recording was of an important
discussion, the assumption was made that the erasure was intentional. Once the material
was gone, nobody expected that it could be recovered, but it was still important to
determine whether the missing bits had been zapped in error (as was claimed) or whether
somebody had deliberately deleted them.
A panel of experts was assembled to examine the tapes and
report their findings to the court. The results were widely reported in the general press,
but in a very non-technical way. Shortly after the panel's findings had been published,
therefore, a now-defunct hi-fi magazine asked me to describe the findings in a way that an
audio-savvy audience could appreciate.
Here's my description, from the Fall of 1974:
It was a typical hot, humid July day in Washington. During
the lunch break on that Monday, word buzzed through the Capitol press corps covering the
Watergate Hearings that there might be a bombshell when Senator Sam Ervin resumed the
proceedings. Wire-service men and TV reporters had received word that the committee was
about to call a mystery witness. Who he was and what he might say monopolized
conversation, driving away the usual comments about Washington's lousy weather, politics,
or who did what over the weekend.
When Senator Ervin banged his gavel, the witness who was
sworn in proved to be the unprepossessing Alexander P. Butterfield, former deputy
administrator to the President and a former aide to H.R. Haldeman. Why had the committee
been wrangling over who had said what to whom, threatening to go to court to get logs of
the President's conversations? He asked, "Why not consult the tapes?"
"What tapes?" Ervin wanted to know.
Why, the tapes President Nixon had had made of virtually
every conversation and telephone call from the Oval Office and other selected spots in the
White House.
As seven senators sat almost open-mouthed, Butterfield
recounted how he had installed bugging equipment throughout the White House, and how it
operated. Obviously, those tapes would resolve the contradictions in testimony between
John Dean and some of the other participants. They would settle once and for all what the
President knew and when he knew it.
There was just one problem -- getting hold of the tapes.
They were still in the possession of the President, and he gave no indication of plans to
release them. That refusal brought about the "Saturday Night Massacre" of
October 20, which in turn brought about the release of some of the tapes early in
November. White House counsel J. Fred Buzhardt had barely finished explaining to Judge
John Sirica that it was impossible to deliver two of the tapes because they didn't exist,
when researchers discovered that one of those which did exist contained a gap of 18
1/2 minutes. And that gap occurred just after President Nixon and H.R. Haldeman began
discussing the Watergate arrests, on June 20, 1972.
Nor was the June 20 tape the only one with gaps. House
impeachment investigators discovered, when they finally got their hands on them, that the
tapes whose transcripts President Nixon released early in 1974 contained numerous gaps,
including one even longer than that on the June 20 tape.
How did the gaps happen? Were they accidental, or a
deliberate attempt to conceal evidence? Were they a case of bad luck for the President,
blotting out information that would exonerate him, or evidence that would lead to
impeachment? Judge Sirica wanted to find out.
To do so, he appointed a team of audio experts to study the
tapes for evidence of physical damage, for possible electronic faults, and to see whether
any sound could be re-created.
The experts who got the job were Dr. Richard H. Bolt,
chairman of the board of Bolt, Beranek and Newman, Inc., acoustic designers of New York's
Lincoln Center Avery Fisher Hall; Franklin Cooper, president and engineering director,
Haskins Laboratories; Dr. James L. Flanagan, head, Acoustics Research Department, Bell
Laboratories; Jay McKnight, consultant to the Scully/Metrotech division of Dictaphone; Dr.
Thomas G. Stockham, Jr. professor of computer science, University of Utah; and Mark R.
Weiss, vice president, Acoustic Research, Federal Scientific Corporation.
Before beginning work, they were approved both by special
prosecutor Leon Jaworski and by counsel for the President. It took several months, but at
the end, the panel of experts declared unanimously that the tapes had been erased
electronically -- and there was the strong implication that the erasures (it took at least
five, and perhaps as many as nine tries to clean the June 20 tape) were deliberate.
How did they know? How could they be sure there were
erasures instead of machine malfunctions -- and that the erasures were deliberate?
What the panel found on the June 20 tape for example, was
basically 18 1/2 minutes of hum. But not a steady hum -- the first five minutes were taken
up with a rather loud buzz, while the rest of the section contained a buzz at a somewhat
lower level. The original contention of White House Counsel J. Fred Buzhardt was that the
hum was caused by [secretary] Rose Mary Woods's lamp and typewriter when she accidentally
caused the erasure. Miss Woods was listening to the tape in question, so the story went,
when the telephone rang. When she answered the phone, she accidentally pushed the record
button and also accidentally kept her foot on the pedal that controlled the machine. The
lamp and typewriter on her desk did the rest -- at least for the first five minutes. Miss
Woods never claimed to have erased the whole 18 minutes.
Buzhardt said that he managed to duplicate this recording
of hum afterwards; but the panel of experts, equipped with the same recorder, lamp, and
typewriter, were unsuccessful in producing a signal that sounded the same or looked the
same under spectrum analysis, in which the frequency distribution of the hum could be
clearly seen.
Instead, according to the panel, the buzz was simply plain
old, garden-variety AC line hum leaking into the recording because of a faulty bridge
rectifier. When the rectifier was replaced, the hum disappeared. This finding not only
cast doubt on the credibility of Buzhardt's testimony, but almost certainly identified
Miss Woods' tape recorder as the one on which the erasure was made.
This did not rule out the erasure's happening as Miss Woods
claimed. Whether the hum was caused by the lamp and typewriter or by the machine itself is
really immaterial. What makes the story seem doubtful is the fact that it takes a
deliberate act to put the machine into record mode.
The tape recorder was a [reel-to-reel] Uher model 5000.
Like most machines, it included a Record Interlock button to prevent accidental erasure.
In order to record a tape, or erase it (which is the same thing, except erasure need not
have any signal present), it was necessary to press not only the Record button, but also
the Start button simultaneously. It stretches the credulity somewhat to believe that she
could have accidentally pressed both buttons reaching for the telephone -- particularly
since, on the Uher 5000, two other buttons were between the Record and Start buttons.
Normally, one would use two hands to press the two buttons.
But even this might be explained away. What is more
difficult to dismiss is the strong evidence that the erasure was not done in one long
sweep. Rather, the 18 minutes contain at least five -- and probably nine -- erasures. Even
the five minutes that Miss Woods claims to have erased is made up of several different
sections.
The question is, "how do they know the erasure is
divided up in this way?" It took the panel much sleuthing to find out.
The real giveaway was something that annoyed
tape-orientated audiophiles since recorders became generally available. Many recorders,
when you put them into the record mode, record a slight click or thump. In the case of the
Uher 5000 -- or this one, at least -- this noise is very small indeed; but it does exist.
By using a chemical solution that rendered the magnetic
patterns on a tape visible, the panel was able to see and photograph this distinctive
signal, and to tell where and how often during the 18 minutes the tape recorder had been
switched into the record mode.
By the same process, another tiny signal, produced when the
machine was switched out of the record mode, was visible. Putting these two bits of
information together, the panel could deduce how many times the recorder had been stopped
and started during the controversial tape section.
In fact, the starts and stops did not match up perfectly.
The investigation showed five separate stop sounds were recorded on the tape, but there
were nine start signals. This could mean a section was erased, and then partially rewound
and erased again, wiping off the prior stop signal. In any event, while nine separate
operations are likely, it is virtually certain there were at least five starts and stops.
It's unlikely that these were accidental. In order to put a
start signal onto the tape, it was necessary to press two widely spaced buttons; and to
put the stop signal on the tape, another button must have been pressed. Therefore, for
every interruption on the erased portion of the tape, three buttons had to be pushed in
two movements -- hardly something one was likely to do by accident. At least not five
times.
Nor could these signals have been produced by stepping on
the foot pedal, accidentally or otherwise. Like the pause control, the foot pedal attached
to a Uher 5000 only affected the tape motion. It did not affect the electronics at all.
But it was necessary to switch the recording electronics on and off to produce the start
and stop signals on the tape.
Someone had to operate the buttons on the Uher manually at
least five times to produce the type of erasure found on the tape. It almost certainly had
to be done on the machine Rose Mary Woods used. Just who did it remains a mystery --
particularly since White House records of who had access to either the machine or the tape
appeared sketchy.
But whoever it was, he or she was not well versed in tape
recorders. The erasure was amateurish, leaving all sorts of clues for the panel of
experts; while a simple single final pass of the tape would have expunged all these
telltale signals. As it stands, apparently whoever erased the tape wiped off a bit,
listened to the next passage, and then rewound and erased again.
The unstated conclusion is that something important was on
the tape, and that someone wanted to make sure all of it was removed. Just what it was
will never be recovered from the tape, as both the erasure itself and the overlay of 60Hz
hum have obliterated it for good.
But the panel did indicate something was, in fact, recorded
there. In the process of erasure, three tiny "windows" were left between the
different erasing operations. These short segments contained speech-like sounds.
So how did the panel know the tapes had been doctored? They
merely reported the only way the erasure could have been made, and left the court and the
public to make their own conclusions. But anyone experienced in the use of tape recorders
must conclude the chances of anyone going through all the necessary moves by accident are
infinitesimal. Barely possible, but extremely unlikely.
Despite subsequent challenges by the White House and
others, the panel stuck to its report. It didn't say who did the doctoring, but it left
little doubt that somebody did.
...Ian G. Masters
ian@mastersonaudio.com
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