Problem with voice recordings on m240

I have a sansa m240 and i need it for voice recordings too. The problem is that it doesn´t reproduce de voice recordings i have that were recorded with other device (the files are .wav)

When i save the recordings that were made with sansa m240 to the computer end then rename it in the computer, if i back with the file that were renamed to the m240 it doesn´t play.

Why is that rapenning?


are you putting it back in the record folder?

convert to .mp3 with:cd ex