Lost all multimedia playing

Hi, I thought I put on some music while scanning old photos. I did not succeed: the loudspeaker icon on the tray is crossed, and says there isn't any application that plays or records sound. No vlc, no smplayer, no youtube, nothing. I tried the tips found on the the net, but none of them worked (or i would not write this letter). I have Tumbleweed with KDE Any help is welcome Thanks, Albert