Bad sound in CS 1.6

[Spectre01]

Well I seem to incounter this issue after spending some time playing CS 1.6 and other HL1 engine games. After around 30 minutes(time may vary) of playing my sound gets very distorted, as in everything having a stuttering echo wich is VERY annoying. If I quit the game and immediately restart it everything will agian be fine for the 30 or so minutes.;(

 

[Beerdude26]

I've got this issue with AoE III :|

Maybe it's sound or video drivers.