As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) FLIGHT CREW CONDUCTED AN AIRBORNE RETURN SHORTLY AFTER DEPARTURE DUE TO A LOUD HOWL COMING FROM THE LEFT OVER WING EXIT. THERE WERE NO ABNORMAL PRESSURIZING INDICATIONS. NO EMERGENCY WAS DECLARED. REPLACED RISER DUCT PER PP ERJ190-21-54875 AND AMM 21-22-01 PG 1-21.