DB measurement doesn’t take into account frequency, I believe. 10 dB at 16,000 hz sounds different to many people (i.e. old people :-) as opposed to 10 db at 4000 Hz. I recently thought of this using my Fuji Xe1 and Xt3 (totally quiet!) and thought of the old days using M2’s and M3’s. Very interesting subject. Always cough right after you press the shutter.