how to convert bunch of .APE files to .WAV using ffmpeg

in one line batch scenario  (on mac osX)

 ls -1 | grep -i .ape | grep -v ^._ | xargs -I% sh -c 'printf "% \n"; WAV=`printf "%" | sed -e 's/.ape/.wav/g'`; printf "$WAV \n"; ffmpeg -i "%" "$WAV" '