As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE THE FLIGHT CREW REPORTED EXTREME STATIC AND NOISE OVER THE HEADSET AND UNABLE TO COMMUNICATE PILOT TO PILOT, PILOT TO ATC OR PILOT TO THE FLIGHT ATTENDANT. AIRCRAFT RETURNED TO IAD. MAINTENANCE INSPECTED AND SOLDERED A BROKEN WIRE ON THE F/O'S AUDIO JACK AND REMOVED AND REPLACED THE OBSERVERS HEADSET. SYSTEM OPS CHECKED GOOD.