But the Lawrence Berkeley scientists used optical imaging and a “virtual stylus” on high-resolution scans of the phonautogram, deploying modern technology to extract sound from patterns inscribed on the soot-blackened paper almost a century and a half ago. The scientists belong to an informal collaborative called First Sounds that also includes audio historians and sound engineers.

David Giovannoni, an American audio historian who led the research effort, will present the findings and play the recording in public on Friday at the annual conference of the Association for Recorded Sound Collections at Stanford University in Palo Alto, Calif.

Scott’s 1860 phonautogram was made 17 years before Edison received a patent for the phonograph and 28 years before an Edison associate captured a snippet of a Handel oratorio on a wax cylinder, a recording that until now was widely regarded by experts as the oldest that could be played back.

Giovannoni’s presentation on Friday will showcase additional Scott phonautograms discovered in Paris, including recordings made in 1853 and 1854. Those first experiments included attempts to capture the sounds of a human voice and a guitar, but Scott’s machine was at that time imperfectly calibrated.

“We got the early phonautograms to squawk, that’s about it,” Giovannoni said.

But the April 1860 phonautogram is more than a squawk. On a digital copy of the recording provided to The New York Times, the anonymous vocalist, probably female, can be heard against a hissing, crackling background din.

The hunt for this audio holy grail was begun in the fall by Giovannoni and three associates: Patrick Feaster, an expert in the history of the phonograph who teaches at Indiana University, and Richard Martin and Meagan Hennessey, owners of Archeophone Records, a label specializing in early sound recordings. They had collaborated on the Archeophone album “Actionable Offenses,” a collection of obscene 19th-century records that received two Grammy nominations.

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