Are you familiar with these meters? They are tiny, all in some 350g and that includes atmospheric composition, particle counters, anemometer, and broadband frequency recording. The actual evaluation you have to do on the PC but the meter is tiny.

I use them a lot when colleagues complain that one of my machines makes "strange noises" and I can then log this statement quantitatively against earlier measurements.

The factoid being that planes are not just noisier than other planes but may be noisier or quieter in certain frequency regions during certain stages of flight. At cruise the 777s are e.g. really quiet all over the spectrum but they are not quiet climbers.
I say inconclusive because I only did a few 787 rides and the noise patterns do not resemble each other ... not even NH's 787 in coach sounds like NH's 787 in coach on a later date.
Only one thing can be quantified without an iota of doubt - the A380 is the best no matter when and where and in what range. Nothing else I have ever flown on even comes close.
Nothing. That was Kleffen's quote and he was friendly enough to correct me. I myself don't recall what I watched on those 787s once I was done with measuring the seat power and the noise level ....
Ah I never had the pleasure myself. But friends of mine brought measurements home from the famed Tu 154 and Ilyushin 96.