Complex sentence: His singing voice was not provided by the usual dubbing actor Adrien Beard, but is in fact the original Lou Rawls recording of the song, however sped up to the same pitch that all of the actor's voices are shifted to sound child-like.
Split into simpler sentences: His singing voice was not provided by the usual dubbing actor Adrien Beard, but is in fact the original Lou Rawls recording of the song. However, Lou Rawls'voice is sped up to the same pitch that all of the actor's voices are shifted to sound child-like.