"Trust me if its a loud sharp whistle then its a small leak, if its any whistle at all there is nothing to worry about, the wet paper works. The noise the rear right hand door of the good old ATP used to play ,some very nice tunes I can tell you.
"
Not necessarily - EMB135/145 front door whistles are mostly aerodynamic whistles caused by the position of the external handle.
If the handle is underflush, or proud, by more than 1mm it whistles like you wouldn't believe.