The old Image DVD sounds poor. It's much less detailed than the later DVDs and the blu-rays. The first 57 minutes are ~8 dB too quiet compared to the rest of the film. It was the last edition, however, to have the full as-released-in-1936 version of the Nonsense Song; for the film's 1956 re-release, Chaplin cut the final verse of the song from the movie.
The MK2 DVD is sourced from superior elements and has considerably more detail, but it has quite a bit of noise reduction. The Criterion blu-ray has the next most NR. The Kinowelt DVD sounds good, but it's slightly compressed. The Scandanavian Soul Media blu-ray has some weird filtering going on between 7 and 9 kHz. The Japanese Kadokawa blu-ray sounds the best to me.
