Although in Norwegian (google translate should work OK), this article deals with the attempt at restoring the audio (and voice) recorded on a piece of tinfoil from the late 1880s. For the speech-codec peoeple, see if you can make any sense out of the final restored piece :)
https://www.nrk.no/kultur/xl/kan-verdens-eldste-opptak-av-edison-ha-ligget-i-en-norsk-kjeller-siden-krigen_-1.13727285
Was recording on tinfoil common back in those days? Very interesting.