Apparently a Frenchman figured out how to record sound well before Edison did. But it took 150 years and lasers to actually play back the sound. Edison's place in history is safe because his system could play audio as well as record. Still, it's hard for me not to find something called a "phonautogram" cool.
If I read the article correctly, they had to take the paper (yes, paper) and scan it optically, and then reconstruct the waveforms for playback. The gadget was hand-cranked, so the playback rate would have been erratic and would have to be corrected for. That sounds like it was really the hard/time-consuming part....historians have been carefully scanning really old documents of various sorts for a while now, but converting those images to sound (while accounting for the wobbly speed of the machine, and any other idiosyncracies it had) is new.