Hi ui670 - what LiveCD are you using? Gotta know that for answers to be accurately provided.
IF its PCLinuxOS KDE 2010x the first thing that people are asked to check - so they can be discounted - is have you clicked on the KMix Loudspeaker icon and turned the volume right up. And make sure the mute isn't ticked. Also at the KMix icon, Select Mixer > Settings > Configure channels and drag the ones required over to the r/hand panel.