Mary Had a Little Lamb

Notes

In 1877, on Edison's first successful attempt at reproducing recorded sound he used the words "Mary Had a Little Lamb".
This first ever "sound" cylinder has not survived (like other tinfoils early recordings), but in 1927 he made a re-enactment reproducing that moment:
"The first words I spoke in the original phonograph. A little piece of practical poetry. Mary had a little lamb. Its fleece was white as snow. And everywhere that Mary went, the lamb was sure to go."

The file widely available on the internet is that re-enactment.