Hi,
First, please refrain from posting to multiple mailing lists at the same time, the developer mailing list is not meant for this kind of questions.
You can use the wav-copy tool to extract a single wav-file from an archive. What you need for this is an accompanying scp file. If you don't have that yet, you can generate it by e.g. running: "wav-copy ark:orig.ark ark,scp:new.ark,new.scp". A line in the scp file will look like:
utt-id new.ark:336166
Now you can use the wav-copy tool to extract a single wav-file by doing "wav-copy new.ark:336166 utt.wav"
There is no way to extract all wav-files at once, but you can easily make some kind of bash script to do that.
Regards,
Peter