No sound at all

My game has been fine but since yesterday for some reason sound no longer plays at all. I’ve redownloaded the game and verified the game cashe but this hasn’t fixed anything. Other games on steam works fine, one thing that I did notice today is that if I my sound manager up then the only sound that will play is the tune when the Gearbox logo is on screen (after the 2k logo) and the game will constantly try to minimise. I the sound manager is not present then the only thing that happens is that I get no sound at all (sorry if I’m going round in circles). As anyone got any ideas?