As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSPECTION TYPE:NAPASSING FL330 WE GOT A LOUD AUDIBLE WHINE AROUND THE MAIN DOOR AREA. I THINK THERE IS AN AIR LEAK AROUND THE MAIN DOOR SEAL? CABIN PRESSURE WAS NORMAL. THE NOISE STOPPED AT FL230 IN THE DESCENT.INSPECTED AND CLEANED FWD MAIN DOOR SEAL IAW AMM 52-10-18 & FIG 401.1 NO DEFECTS FOUND AT THIS TIME.