In November 1981, a music critic from The New York Times traveled to Philadelphia to test a local physician's amazing ability to recognize any piece of classical music merely by looking at the pattern of grooves on a vinyl LP.

The critic handed Dr. Arthur Lintgen several label-less LPs, and was delighted to see him correctly identify the music within seconds merely by looking at the records' surface.

"For his pièce de résistance, Dr. Lintgen spotted the Strauss Alpine symphony, adding with pride – and astonishing correctness – that Strauss was conducting," wrote the critic, Bernard Holland.

Now, a university student from Israel has written a piece of software that goes a step further. Ofer Springer has created a "virtual gramophone" that plays LPs using an ordinary flatbed scanner.

Springer's Digital Needle uses a high-resolution image of an LP captured by a flatbed scanner. (Because 12-inch LPs are bigger than the image glass on most scanners, Springer first takes four pictures and stitches them together into a single image.)

Then, like a needle on a record player, his software follows the image of the groove as it spirals around the record, generating sounds based on the wavelike patterns of the groove.

The results are barely recognizable as the original music, but strangely affecting. Springer has posted samples on the project's Web page.

Springer, a 22-year-old student studying physics and computer science at the Hebrew University of Jerusalem, readily admits the software is almost completely useless. The results are too poor for ripping old LPs and turning them into MP3s. But Springer said he was pleased with the work as a technology demonstration.

"The main purpose was to show an audio signal could be visually recoverable from a record," he said. "For most purposes, there is no point in applying it. Simply using a mechanical player is more suitable."

Springer got the idea one evening after examining an old LP with a magnifying glass. The wave forms created by the tightly spaced grooves led him to believe there must be a way to extract sound from the visual patterns.

Trouble is, only certain mono recordings encode music laterally, in the left-to-right axis of the groove. Many encode sound vertically, in the groove's hills and valleys.

Most modern stereo LPs encode sound in the walls of a V-shaped groove. Each wall of the V is covered in tiny bumps and pits, which are translated into the left and right stereo channels by the needle as it travels down the groove.

Marshall Lisé, an audio engineer with analog chipmaker Xicor of Milpitas, California, said although Springer's idea seems like a good one, it is impractical because he isn't looking at the right part of the groove.

"It's a clever idea, but it'll never work" Lisé said. "If the scanner is looking straight down into the groove, it's reading artifacts of the recording process, not the recording itself."

To read the recording, Springer would have to figure out a way to examine each wall of the V diagonally, Lisé said.

This, in fact, is what expensive laser turntables do. Made by ELP, a Japanese manufacturer, the Laser Turntable uses five separate lasers to read LPs optically. Two lasers guide the head down the groove, two more examine each wall and a fifth maintains the right distance from the surface of the record.

It's a lot more sophisticated than a flatbed scanner, and a lot more expensive. The basic model costs $10,000.

And what was Dr. Lintgen's method? The good doctor didn't examine the individual grooves of vinyl LPs like Springer's software does. Instead, Lintgen studied the patterns of light and dark sections that are easily discerned on most records.

The patterns of light and dark helped him estimate the volume and length of different sections of the piece, which he compared to his deep knowledge of the movements of classical music.

Springer's Digital Needle software can be downloaded from his site for free.