1. A method comprising: reproducing a paper document via a document reproduction system; creating a multimedia annotation for the paper document during the reproduction, wherein the multimedia annotation is an audio sound that is input by a user via a microphone of the document reproduction system; creating a first multimedia document by combining the paper document and the multimedia annotation, wherein the first multimedia document includes a first bar code that encodes the audio sound therein; processing the first multimedia document; decoding the multimedia annotation from the first bar code; extracting the audio sound; and playing the audio sound via a multimedia player.