In the early 1880s, recording sound was a brand new thing. It was so brand new that people like Alexander Graham Bell and his buddies were still experimentin' with the best way to make it work. The Smithsonian has some of these trial-and-error recordings, and using 3D optical scanners, they've been able to play them back for the first time in over a century.
Volta Labs was founded back in 1880 by Alex Bell, his brother Chuck, and their cousin Chichester, which was apparently a name back then. Tommy Edison had already invented the phonograph in 1877, but it didn't work all that well, and the Volta boys were determined to invent something better, which they did by 1886. In those six years, though, they tried a bunch of stuff that didn't work all that well, including rubber, beeswax, tin foil, brass, and recording audio on glass discs using beams of light (which seems impossibly futuristic, to be honest).
Trying to play the audio stored on these discs the old-fashioned (or, contemporary) way would be too destructive, and it took until just this year for enough smart people to get enough sophisticated equipment in one place (the Library of Congress) to figure out what's on these things. To do so, they didn't physically touch them at all: instead, the discs were scanned with high-resolution optical sensors, and then software played a virtual needle along the images of the grooves in the discs, extrapolating what sound would come out.
Click on the links below to listen to the audio from these discs, and as you do, remember that these are the voices of some of the original hardcore tech geeks, and that they were making these recordings before the invention of Coca-Cola.