In yesterday’s PlayStation Store update, Sony released several official XMB themes for the PlayStation 3. What they failed to mention was that the themes come with custom sound effects, which can be heard when navigating the XMB. Currently, the Heavenly Sword theme, Mesmorise theme and the Ratchet and Clank theme have sound effects.
The current Theme Creator tool does not support sound effects, but look out for a new version of the tool soon. In the mean time, head over to the PlayStation Store and download some themes to see for yourself.