Hi there! New user I have an i40 (sonata is the us version I'm sure) the last couple of days I've been hearing a loud air sucking noise when Im going uphill in a lower gear say 2/3 but once I get to a speed it goes again back to normal, it lasts maybe 3/4 seconds, any help would be much appreciated

 

Has the air filter been recently serviced? The air filter box may be unlatched, also possibly the intake duct or fresh air ducts may have come loose.