Perhaps I should clarify a little.
Engine noise and slipstream noise are about average to maybe a little below average for a rear engine jet. Of course it is extremely quiet up front, forward of about row 14. I too have flown aboard many AA
F100's. At one time I was based in Chicago and living in Pittsburgh and made the commute every week. I chose AA
about 90% of the time because all of their flights were either MD80's (my personal favorite) or F-100's.
Personally, I think the F-100 is more comparable to the Bac111 than the DC9 although it is quieter than both. The F-100 rides like the 111 (stiffer wing than the DC9), and it has the same little oval windows. The DC9/MD80 seats seem to be a bit wider, windows are larger etc.
Back to the noise issue. The absolute worst airline seat I have ever experienced is seat 31F on the US MD81. No window, right next to the first stage compressor, right in front of the lav with tons of vibration and a lot of yawing motion (very turbulent flight). My head still hurt four hours later when I checked into my hotel in Memphis. With that being a ten on the discomfort scale (mine anyway) row 18 on the F100 would be a five. If you have the chance to go up to row 8 take it. You wont be miserable in 18 by any means but row 8 would be much better in all respects.
Im still hoping for some insight from a qualified contributor (pilot or mech on the F-100) as to the possible source/cause of that buzzing fan I mentioned above.