my t3 has weird sound issues too!
once every 2 or 3 days (while on for 12 hours a day on route), it'll scream every sound in the machine at max volume for about 1-2 seconds. scares the s#it out of everyone in the shop. so funny to watch everyone jump out of they're skin!
i know t3 has always had sound and reset issues (especially during assault) due to the design. it's even in the operator's memo on stern's site, even w the newest rom and sound version.
btw i put all LED flashers in to battle the resets and it cut it by about 80%
-jon