Sound recordings still available to us go back as far as 1878. In this collection at Listverse, you'll find historical recordings of Florence Nightingale, Pope Leo XIII, and other audio firsts.
One of the strangest ones is the recording of castrato Alessandro Moreschi, a man castrated as a boy to keep his singing voice from changing during puberty (featured previously at Neatorama).
Other recordings listed in the article include an exorcism, the recording of the 1978 killings in Jonestown, and even the Sounds of Hell (yes, it's a hoax, but quite interesting).
From the Upcoming ueue, submitted by .