The below link will give you an idea. IMO Flörsheim gets off easy on this map as they get lots of overflights depending on the wind. Places like Kelsterbach, Raunheim, Rüsselsheim, Neu-Isenberg are definitely loud. In my experience the towns between the black and red lines are still quite loud, i.e. if you're in your backyard and a plane takes off you'd have problems carrying on a phone conversation for a minute. Between the red and green lines (where I live) the planes have usually reached a decent altitude and aren't so bothersome.
Of course you could avoid it entirely by living North of the Flughafen in the Taunus area. Also in Frankfurt proper there isn't much noise from aircraft.
http://atlas.umwelt.hessen.de/servlet/Fram...ten/h_2_2_2.htm