The invention relates to a method for determining, by reanalysis, a vibratory environment of a coupled vehicle/passenger system, the vehicle being subjected to external forces Fext and being coupled to a new passenger comprising x=1, ...N payload(s), at the level of vehicle/passenger interfaces Ix, the method comprising a step DET1) for determining, based on reference interfacial acceleration [gamma]x_ref of a reference passenger, the interfacial acceleration [gamma]' x relative to the new passenger using the following equation (I).