What was found
DURING DESCENT FROM AROUND FL200 A LOW LOUD HUM STARTED. WE WERE AROUND 295-300KTS VIBRATION FELT IN FEET FROM LEFT AND RIGHT PILOT. WORSE VIBRATION FELT FROM THE FLOOR INLINE WITH THE MAIN CABIN DOOR. VIBRATION AND SOUND STOPPED AT 11,000FT IN LEVEL OFF AFTER AIRCRAFT SLOWED. HIGHER PITCH HUM AND VIBRATION FELT AT LOWER AND SLOWER ALTITUDE UNTIL FULLY CONFIGURED FOR LANDING. PERFORMED INSPECTION FROM SQUAWK 2.1. FOUND UPPER LT & RT SIDE WING TO BODY PANEL SEALS TO BE SEPARATED IN MULTIPLE LOCATIONS. FOUND LOWER FWD FUSELAGE WING TO BODY PANEL SEALED INCORRECTLY. REMOVED OLD SEALANT AND REPLACED. IAW MM 53-04-30-400-801-A. AND NJA TC E50-53-0001_1.