[MSN] Sonic Fingerprints Safeguard Art.

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Sonic Fingerprints Safeguard Art


By Nicole Martinelli
02:00 AM Jan, 09, 2007

A near-perfect copy of a precious funeral urn called the Cratere dei Niobidi
sits in an Italian cafe close to the University of Palermo. Restorer Lorella
Pellegrino spied it there one morning before meeting with professor Pietro
Cosentino, a geophysicist, to analyze the actual fifth-century-B.C.
artifact.

They were examining the real urn to see if it was healthy enough to loan for
an exhibit in Beijing when Cosentino stumbled on the idea of using "sonic
fingerprinting" to help end Italy's ongoing problem with faked and stolen
artwork.

"We started joking about how (the urn) might come back from China cloned,"
said Pellegrino, who works with the former seismologist much as a physician
might with an X-ray expert. "That was when Cosentino realized the analysis
could serve another purpose."

Cosentino, 65, started using sonic tomography to study art about a year ago.
Working on the principle that every object emits a distinct vibration, each
piece of art or cultural artifact is fitted with a network of sensors, then
tapped with a small rubber hammer. Recorded vibrations form a unique sonic
fingerprint capable of distinguishing even works made in pairs or series.
The process is noninvasive, takes just a few hours and can be used on stone,
wood and ceramics.

"We're used to having to trust appearances; this really expands our
knowledge," said Vincenzo Abbate, director of Palermo's Museo Abatellis, who
let Cosentino and Pellegrino try their system on a statue of archangel St.
Michael. "As for using it for security, we do everything possible to prevent
theft but are always interested in new methods."

In addition to providing vital information about the "insides" of a work --
including structural flaws or fractures that could make restoration
necessary or keep the work from traveling -- the fingerprint provides a
valuable weapon against forgeries and theft, since the unique identifiers
could be recorded and stored for future reference.

Italy, chockablock with art treasures, has long struggled to hold on to its
vast patrimony. Legal disputes between auction houses or collectors and the
Italian government are frequent; Interpol ranks Italy third in the European
Union for stolen treasures.

Mark Dalrymple, founder of the Council for the Protection of Art Theft, said
he finds the sonic fingerprint idea "interesting" but cultural items'
authenticity and provenance could still be in doubt without controlled
results from enough known objects.

Christie's representative Toby Usnik said the method might "be useful to
track stolen art, (but) this kind of a system could lend itself, in the
wrong hands, to false identification for inappropriate purposes. "

The sonic fingerprinting system, in the process of being patented, does have
a few drawbacks. Just like X-rays, the scans must be performed every few
years to provide up-to-date pictures. The cost of the machine -- 15,000 to
20,000 euros (about $19,000 to $26,000) plus trained staff to run it --
could keep museums from having one in-house.

"My dream is to ID Italy's art," said Cosentino. "I am not necessarily
pushing to sonic fingerprint every single object -- there is so much of it
-- but we need to have accurate records about what we've got."

Ultimately, public awareness may be the most effective security device. A
shamed collector who realized he had bought a stolen terracotta sculpture by
Arturo Martini recently phoned Milan's Museo della Permanente to say he had
dropped it off outside in a black trash bag.

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