This is one of the few known recordings of Houdini’s voice. He made this in 1914 on an Edison wax cylinder machine.
“Ladies and gentlemen. Introducing my original invention, the Water Torture Cell. Although there is nothing supernatural about this, I am willing to forfeit the sum of 1,000 dollars to anyone who can prove that it is possible to obtain air inside of this torture cell, when I am locked up in it in the regulation manner after it has been filled with water. Should anything go wrong when I’m locked up, one of my assistants walks through the curtain, ready to rush in, demolishing the glass, allowing the water to flow out in order to save my life. I, Houdini, October the 29th, Nineteen Hundred and Fourteen, Flatbush, New York.”
UPDATE: The Houdini Museum has posted a version of this recording that has been cleaned up to remove some of the background static. The video has some additional information on the recording.