A technique developed at Lawrence Berkeley National Laboratory allows researchers to create digital copies of old records without damaging the fragile discs.

The technique uses a light sensor to capture images of the record’s groove. A computer then uses these to reconstruct the recording, filtering out any background noise.

The technique should be able to retrieve sound from even the earliest grooved recordings from the late nineteenth century, says Mark Roosa, director of preservation at the Library of Congress. The wax or metal cylinders on which these recordings were made had been considered too deteriorated to salvage, he says.

Historians could even hear the words of Thomas Edison, the father of recorded sound.