It is not very well known that Debussy made recordings of himself playing the piano. He recorded several of his own pieces on piano rolls, to be played on a mechanical Welte Mignon player piano. The Welte "reproducing system" could capture the performance of the pianist, and reproduce it more or less accurately, complete with dynamics and pedalling. The piano rolls are now in the Simonton collection at the University of Southern California. There would probably also exist some copies of the rolls elsewhere.
I know of two CD-recordings made of the rolls:
Acoustic recordings are of course more interesting when we want to get an impression of Debussy's playing, since piano rolls cannot be completely trusted to faithfully reproduce what the pianist played. Unfortunately there are not many acoustic recordings of Debussy. He did however make a recording accompanying the singer Mary Garden for the G & T (Gramophone and Typewriter Co.) in 1904. These recordings can also be found on the CD Pierian 0001.
The songs they recorded: