Paul Ginsberg has become a familiar face in the courtrooms of New Jersey,
making a career of sifting though the muck of damaged and muffled tape
recordings to sort out the voices and sounds that have been used as evidence
in some of the nation's high-profile court cases.

Now, Ginsberg - who refers to himself an "audio archeologist" - hopes to
tackle what may be the most famous audio enigma of our time: What was on the
notorious 18 1/2-minute gap on one of President Nixon's White House
Watergate tapes?

"This is a piece of history, a missing piece of the puzzle of the fabric of
our time," Ginsberg said, explaining that the missing minutes could "shed
light on what really went on in the Oval Office."

The opportunity to study the tape - which involves a conversation between
Nixon and chief of staff H.R. Haldeman just days after the Watergate
break-in - was made possible by the directors of the National Archives, who
have kept the original recording virtually untouched in a climate-controlled
vault for decades.

This year, on the 30th anniversary of Watergate, Archives officials have
decided to allow an expert - or experts - to take advantage of the quantum
advances in technology in an effort to unearth any residual signal that
could restore the missing conversation.

Initial analysis during the Watergate investigation showed the 18 1/2
minutes had been obliterated as a result of multiple erasures. Nixon's
secretary, Rosemary Woods, claimed she may have been responsible for some of
those erasures by hitting the wrong button while transcribing the recording.
Others believe the erasure was deliberate to cover up a particularly
incriminating statement by Nixon.

Whatever the cause, the contents of that conversation have remained a source
of tantalizing speculation.

The National Archives has imposed a two-part test - offering the experts
simulated recordings that have been recorded, and then erased, to see if
they can recapture any of the original material. One of the main concerns of
the National Archives is that no harm is done to the original recording.

Ginsberg, who operates Professional Audio Laboratories, is one of a handful
of individuals under consideration for the restoration job. The exact number
and identities of the others has been kept confidential by the National
Archives.

Ginsberg - who has consulted for the CIA and once smuggled a recording
device into the agency's headquarters in Langley, Va., as a prank - said he
has completed the first test and is awaiting response from the National
Archives to move on to the second stage.

A lifelong technology buff, Ginsberg has built his own lab from the ground
up, creating a basement "tape cave" in his Spring Valley, N.Y., home crammed
with virtually every type of recording device and signal tester available on
the market today.

Ginsberg's expertise has made him a familiar face not only in New Jersey
courtrooms, but at trials throughout the nation. He has worked on some 1,600
court cases during his 28-year career.

He has worked on tapes of everything from the garbled conversations of Mafia
godfathers to the dying words of the victims at the Branch Davidian compound
in Waco, Texas.

It is not only technology that sparks Ginsberg's success, but his knack for
innovation.

In seeking to analyze the test tape, for instance, he modified a 60-channel
recorder - the kind used for taping police dispatches - and ran the tape
through an "antique" recorder that allowed it to pass over the playback
heads at the same speed as the original Nixon recording equipment, an
excruciatingly slow 15/16 of an inch per second.

After rewiring the tape heads on the 60-channel machine, he had to align the
second recorder to draw the tape at the proper speed. After a couple of
tries, he came up with the simplest solution - he propped the second machine
on a cardboard box that happened to be the right height.

Ginsberg said his hope is that the erasure of the original tape was
imperfect, that a speck of dirt may have been on the heads, that the heads
may have been minutely misaligned, or some other defect may have prevented a
complete elimination of the original magnetic signal. By splitting the tape
into 60 channels, he hopes to find whatever residual signal may be left.

"Once I knew which tracks corresponded to the tracks on the original
equipment," he said, "I knew where to focus the telescope."

Ginsberg acknowledges the chances of recovering the full recording
are slim.

But Ginsberg remains hopeful. "My heroes are Thomas Edison and Sherlock
Holmes," he said, "and they never gave up."