For those who follow, I finally find the way to mix (simpler than I thought) import Sound.ALUT playSound :: IO () playSound = withProgNameAndArgs runALUT $ \ _ _ -> do ↠ buffer1 <- createBuffer $ Sine 440 0 1 ↠ buffer2 <- createBuffer $ HelloWorld ↠ [source1,source2] <- genObjectNames 2 ↠ buffer source1 $= Just buffer1 ↠ buffer source2 $= Just buffer2 ↠ play [source1,source2] ↠ sleep 2 ↠ return () main = playSound (sorry if unicode if ugly, I don't know what to do with spaces) _________________________________________________________________ Téléphonez gratuitement à tous vos proches avec Windows Live Messenger  !  Téléchargez-le maintenant !  http://www.windowslive.fr/messenger/1.asp