What was found
F/O SLIDING WINDOW SQUEAL, RTFL. HIGH PITCH NOISE EXTREMELY LOUD, CREW UNABLE TO COMMUNICATE. UNABLE TO SILENCE OR REDUCE NOISE BY APPLYING PRESSURE TO WINDOW. IAW CREW VERBAL, NO NOISE UNTIL LEVEL CRUISE AT FL36, WITH 8.6 DIFF PRESS APPROX 1:10 INTO FLT, DESCENT TO FL32.8 AT 8.0 DIFF PRESS, NOISE WENT AWAY AND DID NOT RETURN, ADJUSTING CRANK NO HELP, COULD NOT PINPOINT EXACT ORIGIN, SEAL APPEARS WORN ON AFT UPPER & LOWER CORNERS. REPLACED WINDOW.