Sur les conditions aux limites de l'équation du son

A wave theory of room acoustics should account for those of Sabine's results which are substantiated by facts. These are discussed, and it is shown how the boundary condition conducive to the notion of specific normal impedance is most naturally introduced. However, the consequences of that hypothesis do not seem in good accord with experiments, in one simple case at least; caution should therefore be used when applying this boundary condition. A more involved condition is tentatively suggested, taking into account two specific impedances: one normal and one tangential.