A method for determining, by reanalysis, a vibratory environment of a coupled vehicle/passenger system. A vehicle is subjected to external forces Fext and is coupled to a new passenger including multiple payloads (e.g., x=I, . . . N payload(s)). At the level of vehicle/passenger interfaces Ix, the method comprising a step DET1) for determining, based on reference interfacial acceleration γx_ref of a reference passenger, the interfacial acceleration γx′ relative to the new passenger.