I had a bit of trouble tracking down a decent sample of Buster Keaton's voice, as the majority of Youtube material is either taken from one of his silent movies or features some cameo/supporting part/etc. that he did when he was over 60 years old. However, here's an excerpt from one of the more obscure "Keaton & Durante" - movies, filmed towards the end of the Prohibition era - a mere five years after the photo I use as my avatar was taken!
Keaton makes his appearance just after the 30 second - mark. (He's the guy who's daydreaming about some woman, only to be handed a huge fish.) Meanwhile, enjoy the antics of Jimmy Durante!