As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN CRUISE FLT, LOUD MID FREQ NOISE AVAILABLE IN FWD GALLEY LASTING -2HOURS. POSSIBLE IL DOOR SEAL LEAK. CHANGED CABIN ALT BY 500' WITH NO EFFECT. RESOLVED ON ITS OWN.// CHECKED & CLEANED DOOR SEALS AT 1L DOOR, PERFORMED PRESSURIZATION TEST IAW AMM 05-53-00-780-002-A01, NO LEAK OR LOUD NOISE NOTED DURING TEST. OK FOR SVC