Hi,
It s not the first time i m using Audacity and making projects with it. But this time, I cannot hear what I recorded ! I tried via “edition” “preferences” to have my computer recognizing my Edirol but I can t hear anything !
What can I do ?
Assuming you are on Windows I moved this topic here. There is no point posting a question in English on the French forum - no one will be able to understand it. 
Open Audacity’s Device Toolbar and choose the correct playback device. Are you trying to listen on the Edirol or your built-in sound device?
You may need to go into the Windows sound control panels to unmute the device you are trying to play to. What version of Windows are you using?
If Audacity can’t see the Edirol at all, restart Audacity. What version of Audacity do you have? See Help > About Audacity… . What Edirol device do you have?
Gale