Experts Discuss Missing Portion of Nixon Tapes

Sept. 21, 2000 -- Can today’s technology help extract the sounds of silence from the famous 18 ½-minute gap in the Nixon White House tapes?

The inconclusive conclusion reached today by the National Archives is no — at least not yet.

“We called in a number of experts to give us some advice on whether there is technology out there today that might help us recapture the sound on this 18 ½-minute gap,” said Susan Cooper, a spokeswoman for the National Archives.

Public and private sector audio experts gave presentations to the National Archives and Records Administration Advisory Committee of Preservation on the current state of audio restoration technology.

A Bit of Hiss-story

The meeting’s focus was the infamous 18 ½-minute patch of buzzes and clicks in the middle of a recording made June 20, 1972, three days after the break-in at the Democratic National Committee headquarters.

“It’s just blank,” said Christoher Beam, former National Archives staffer who was one of the first to hear the tapes nearly two decades ago. “There’s a kind of fuzzy sound — a kind of light static-y sound, and that’s it. … Then all of a sudden it plops right in the middle when Nixon is meeting with [H.R.] Haldeman.”

Nixon’s secretary, Rose Mary Woods, testified in court that she must have pushed the wrong button on a recorder while transcribing the tapes, accidentally recording over at least part of the original conversation. A panel set up in the 1970s by federal Judge John Sirica, who presided over the Watergate criminal trials, concluded the erasures were done in at least five separate and contiguous segments.

The group of audio experts revisited the infamous erasure, discussing modern restoration techniques, which are far superior to what existed in the ’70s, to see if they might help fill in the long gap. Or not. Experts not at the meeting said a lot of the technical viability of retrieval depends on the actual tape in question.

“If you look at it in terms of black and white, erase is just that: It’s gone,” said Graham Newton, who runs Audio Restoration in Don Mills, Ontario. “What we’re dealing with is degrees of erasure.”

Technical Questions

A group of technical experts in the 1970s found that the machine that did the erasing was a Uher 5000 — a machine Woods often operated — not a Sony TC-800B, which had done the original recording. (See sidebar.)

As the new batch of experts reviewed today’s technology, several audio experts not involved with the meeting told ABCNEWS.com there are several variables in addition to advanced restoration techniques that should be looked at in determining whether or not the erased audio is retrievable, such as the kind of machine that did the erasing.

The fact that it was a different machine makes it slightly more possible that audio could maybe be retrieved. But that alone does not make it probable. Other questions to be considered include: Was it in good shape? Was the erase head new or worn? Also, how many times was the passage erased?

“These kinds of restorations fall quickly into patterns of likelihood and less likelihood,” said Allan Tucker, president and chief engineer at Foothill Digital based in New York. “If I were to hear it, I’d give you a likelihood percentage and give it right off the bat.”

Audio Tech

Analog audio is laid down on tape in strips, or stripes, off a record head, which sits behind an erase head. Basically, the erase head is designed to lay down a strip thicker than the audio strip laid down by the record head to ensure complete erasure. If the erase strip misses part of the recorded audio strip, there is still audio on the tape.

Think of laying down a very thick line chalk on a board, said Newton, and then wiping a thicker eraser over it. If the strips are not completely lined up, a tiny sliver is left. Essentially, this could be the case with the missing audio.

“A very small track like that might leave enough of a recorded track to get something from it,” said Newton.

A system by Sonic Solutions is one of the very few in the world that might be able to restore sound off something as low level as the missing 18 ½ minutes, said Tucker.

“This system enables us to resolve extremely low level signals and strip away through expansion and compression techniques and complex filtering … the stuff that is obfuscating the program that you’re trying to get to,” said Tucker, adding you need to detect something first.

“It’s always up to the ears,” said Tucker.

But not today.

None of the out-of-house experts has heard the 18½ minutes in question, though, and they didn’t hear it today, said Cooper.

Today’s meeting was called to discuss the technology that’s developed since 1974 and to draw up recommendations for the archivists of the United States. The committee mostly agreed with earlier findings that it is highly improbable for erased speech from the analog tape to be recovered. But it also left the door open for unknown technology possibly to fill the gap.

“We’ll decide from there how to proceed,” said Cooper.

ABCNEWS’ Sarah Nakasone and The Associated Press contributed to this report.

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