Chaplain himself was very uneasy about doing talkies. He wanted to make sure that if the 'Little Tramp' ever broke his silence, it would be for something meaningful.
As for the comedic aspect, there's one scene where he does a dance with a giant beach-ball-style globe that's pretty funny.
(For what it's worth, I've heard that prints of this film were among the many things that the Nazis collected to burn in Germany. Hitler was furious with it.)