The only even slightly accurate way to determine this would be to compare recorded audio of similar aircraft at similar distance/setting.
Then contrast/compare recorded audio signals in DAW environment with spectrum analyzer.
Even then it would be comparing apples to oranges.
My 2 cents:
video 1 shot just prior to leaving for Walter Reed, bg noise is Marine 1 waiting outside.
video 2 shot at Walter Reed, bg noise is aircon.