You may have noticed that the Library of Congress just decided to preserve some sounds or recordings. Here are some links to hear them.
The first sounds ever recorded. They were not meant to be played back only to observe the tracings on blackened glass plates. Now a way has been found to hear them. Listen to them at First Sounds.
Take Me Out to the Ball Game by Ed Meeker. Hear all the words in an mp3 file at Public Domain 2ten.