As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNBEARABLE OCARINA-LIKE HOWLING NOISE IN VICINITY OF F/O'S FWD INSTRUMENT PANEL & ABV 2.6 FOUND WIPER MOTOR ACCESS PLATE LOOSE. SECURED SCREWS ON PLATE REF AMM. SEALANT CHECKS OK. PRESSURED AC, NO NOISE OR LEAKS NOTED AFTER TIGHTENING PLATE.