What was found
CLIMBING THROUGH 9000 FT MSL, THE WINDOW BEGAN A LOUD VIBRATING HOWL. AT 11000 FT MSL, SOUND WAS UNBEARABLE WITH ATC AND INTERCOCKPIT COMMUNICATIONS EXTREMELY DIFFICULT. FOUND THE RT SLIDING WINDOW SEAL WORN. R & R THE SEAL IAW AMM 56-12-01-8, REV 89.01 07-13-17. OPS AND LEAK CHECKED GOOD.