PCTV sound problem

Title: PCTV sound problem

Hi,dear all:
 
        I have a PCTV Rave and I use bttv-0.7.107 to drive it under linux.
 
        Now I can tune the channel frequencies and get video well but no sound I can hear only cacophony from earphone.
  
        Could you have some ideas to resolve this problem?

        Thanks in advance!

Fangli