Help - Lost ATC sound

Can anyone point me in the right direction?I seem to no longer have any ATC/pilot sound when using the ATC. Aircraft sound works fine, but when selecting the various options from the ATC menus, I hear nothing.Sound is configured with Voice turned on, and sound devices both use default.It was previously working, I just wonder if I have inadvertantly switched it off somehow.Cheers,Stuart{EDIT] - Ignore this post, have solved what was causing the problem. But in case anyone else experiences the same problem, here was my solution. I had been playing around with my motherboards Sound Manager and had changed from Quadrophonic to 5.1. Seems since my speaker system did not support a front centre speaker I lost the ATC sound. Reverting to Quadrophonic solved the problem.