What was found
DURING THE CLIMB THE PASSENGERS REPORTED HEARING HIGH PITCHED SOUND. WE VERIFIED THE SOUND AND THAT THE PRESSURIZATION WAS OPERATING NORMAL. THE SOUND STOPPED AS WE CLIMBED TO A HIGHER ALTITUDE. PRESSURIZED AIRCRAFT ON GROUND WITH APU. CHECK AIRCRAFT FOR AIR LEAKS NO OBVIOUS LEAKS NOTED, NO NOISES NOTED. DEPRESSURIZED AIRCRAFT ASND OPENED MAIN ENTRANCE DOOR. INSPECTED MED AND SEAL AND FOUND DEBRIS AND OILY SUBSTANCE ON DOOR WHERE SEAL RESTS. CLEANED SEAL AND DOOR , OPS CHECK GOOD. WORK DONE REF CE-700 AMM CHAPTERS 21-30-00 AND 20-52-20