Row 1 on a nearly new A330 is an extraordinarily quiet place to be, far quieter than even the A340-300.
I always felt that the A340 is louder than the A330 in the forward fuselage (business class) but more quiet aft of the wing.
Probably the larger diameter Fan of the A330 is significantly quieter, while the stronger jet is louder. Both are quite loud directly behind the wing during climb, once in cruise this fades away a bit. Seems mach number related.
777 is very loud at the forward wing root with the slats deployed. Also row 1 seems to be quite loud (supersonic airflow around the upper nose section with relatively thin skin), never found that on the Airbusses.
Some elements of the ECS are extremely loud as well, there are some internal circulation fans mainly running on ground in the forward cabin which are loud like hell.
Babies are indeed an issue in the A380, you hear them all through the aircraft. And in economy with the cheap headsets you can follow the soundtrack of 8 movies around you... A certain noise level is not that bad.