To develop methods of predicting radiated noise that can be used in design offices, it is essential to formulate hypotheses to simplify the general problem. The expression of the acoustic presssure autospectrum for quasiplane surfaces in far field is used, obtained from the Green’s function, which depends on: the Green’s function, the cross-spectral density function of the normal acceleration on the body. The spatial distribution of the vibrational field on the vibrating body is, in an industrial context, very difficult to obtain, as it would require too many measurement points. It is therefore necessary to approximate it, and to this end it is assumed that: the vibrating body can be approximated by a combination of elementary surfaces; these surfaces are thin plates; the energy of each mode is uniformly distributed in a given frequency band. Once the vibrational field has been characterized in this way, it is possible to deduce the acoustic radiated pressure. A number of validation tests were carried out, which demonstrated close agreement between the computed and experimental data in the two following cases: a baffle plate and a box.