My current hearing tests lamentably note a "profound " loss of hearing in the frequency range that directly corresponds to the passing frequency of the R1830 powered props of PBY-5As.
We flew them up the shore of Hudson's Bay when the harbour ice became too "liquidy" for the R1830 DC3s on wheel skis. The PBYs were ex military, converted to haul 26 pax and or/freight.
As a (very young) crew man, I would stand directly behind seat 01 during take-off and landings. The bulkhead of the PBY has a cut-out that gives an unhindered "pilot's eye view" of the proceedings - to a standing person - (the nearest Govt rep was + 1,000 miles due south of these proceedings). Unfortunately, this position placed the eager observer directly beneath the arc of the props, with the tips of the near supersonic tips passing mere inches above the plexiglass,
The PBYs produced tremendous noise and drama - especially during open sea ( Hudson's bay is Big) takeoffs, but the DC3s seemed to produce more elegance and music (to my young ears) .
Today I miss some of my hearing ,,,,but I most certainly treasure all of the memories!!!