yes, interior noise can be measured and tested ... as I recall from my 767 flight test engineering days at Boeing, interior noise was about four hours of ground test time and about the same of flight

in contrast, takeoff and approach noise tests (on a 737-200 with two different engine configurations) were an effort that spanned several weeks ... due to wind limitations, some days we'd get a 20-minute flight with only one or two valid test conditions; other days we could spend four or five hours flying the test patterns


my comment about subjectivity is based on the fact that a statement such as "... long haul Airbus planes are much quieter than Boeings" reflects that the passenger is in the environment for hours at a time, and is thus more conscious of the personal impressions of comfort or annoyance ... for someone on the ground near the airport, a single takeoff or approach event most likely lasts less than a minute