Hello vudooz,
If the issue persists with multiple sets of earphones, and it happens with all audio/video content, that leaves only a couple of possibilities.
If you have all your data saved on your computer, you can use iTunes to restore the iPod Touch and setting it up as a "new" iPod after the restore by following the steps in this article:
http://support.apple.com/kb/HT1414
If restoring and setting up as new do not resolve, you'll want to arrange for service.
Charles