As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: DOOR 1L LOUD NOISE IN FLIGHT AT FL 370 CABIN ALTITUDE STABLE 7,400. CONTINUOUS WHISTLE NOISE. STOPPED DURING DECENT PASSING FL 320. FOUND LANDYARD FROM 1L DOOR SLIDE COVER HANGING DOWN. REINSTALLED IAW AMM 25-62-50.