Another go at Nixon tapes

For nearly 30 years, historians and audio experts have believed that nothing

remains of the tape-recorded conversation that once filled the infamous

18.5-minute gap on President Nixon's White House tapes.

But Steven St. Croix, an audio technology expert, told a National Archives

and Records Administration panel Sept. 21 that it might be possible to reconstruct

the conversation through highly detailed scanning and computer analysis

of the magnetic material on the tape.

The tantalizing portion of the tape is believed to have recorded a June

20, 1972, conversation between Nixon and his chief of staff, H.R. Haldeman,

about the Watergate break-in that occurred three days earlier. Ultimately,

the Watergate scandal forced Nixon's resignation in August 1974.

Since late 1973, when the gap was discovered, conversation on that part

of the tape has been considered lost forever. Extensive analysis concluded

that the conversation was erased and recorded over, possibly several times.

All that remains is a buzz interrupted by clicks, pops and changes in volume.

The buzz is believed to be "electrical noise" caused by the electricity

that powered the tape recorder. The pops and clicks were probably caused

by starting and stopping the tape recorder, a 1974 analysis concluded.

At the time, experts concluded that "recovery of the speech is not possible

by any method known to us."

But St. Croix, president of Intelligent Devices Inc., insists that "erasure

is never 100 percent." Even after multiple erasures, some of the magnetic

particles on the tape are likely to retain the pattern they assumed during

the original recording, he told the NARA Advisory Committee on Preservation.

Detailed scanning of the minute magnetic particles that make up the recording

medium of the tape could reveal traces of the original conversation, he

said.

St. Croix proposes to scan the tape with an array of 100 to 200 magnetic

readers. Each reader would examine a band of tape that is one-hundredth

to two-hundredths the width of the whole tape, which is about a quarter-inch

wide.

The readers' findings would be fed into a computer, which would filter out

noises such as the buzz. What's left would be the dialogue between Haldeman

and Nixon — or, if the 1974 investigators were correct, perfect silence,

St. Croix said.