From The Atlantic:
…But there are sound recordings that survive from as far back as the 1860s, '70s, and '80s. It's just that, until very recently, they were unplayable. We no longer had the right tools, and even if we had, playing them would ruin the wax cylinders or fragile records upon which the sounds were stored. But over the past few years, physicists have developed tools for creating 3D scans of the old records and converting those scans into playable audio files. Last year, they released the oldest playable American recording, a series of sounds from an 1878 demonstration of sound-recording technology in St. Louis. In it, you can hear laughter, a song, and some counting, all spoken into the world by people of another century. But until today, the voice that spoke that age of far-traveling sound into being has remained unknown — no living person had ever heard it. What did he sound like? “Did Bell speak with a Scottish burr? What was the pitch and depth of the voice with which he loved to belt out ballads and music hall songs?” Bell biographer Charlotte Gray asks in Smithsonian. He had lived in England, Canada, the eastern United States. He summered in Nova Scotia where people spoke Gaelic. How did all these influences combine in his speech? And now Gray has her answer. The Smithsonian has released audio recovered from a wax and cardboard disc dated April 15, 1885. In it, you can clearly hear the inventor speak the words: “Hear my voice — Alexander Graham Bell.”
More here.