As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DESCENDING THROUGH 16,000FT WITH 68% N1/SIDE AND ENGINE ANIT-ICE ON, THE RIGHT ENGINE ROLLED BACK TO 42% N1. HEARD BANGING FROM THE RIGHT ENGINE THAT LASTED 3 OR 4 SECONDS WITH ABOUT 5 BANGS. THEN THE ENGINE RETURNED TO THE ORIGINAL POWER SETTING.