03-10-2012 08:26 PM
On your XMB go to sound settings and then your audio configuration, check whether DTS 5.1 Ch is enabled in the check list. If it is uncheck it and try the game again.
With many people's set up games will not like DTS even if audio works fine on the XMB.
If that doesn't work try it the other way disabling the dolby 5.1 and enabling DTS.