The tool presented enables the sound behaviour of a room to be objectified on the basis of the representation of the characteristic function (CF) of said room.In this paper, we study characteristic functions, defined from the impulsive responses measured at different points in the room, that are obtained in churchesand cathedrals. These CFs show a variation that correlates with the distance from the point of measurement and the source. An analysis is carried out on the relationship between this variation with those acoustic parameters that depend on the distance to the source: C50, C80,and G. In addition, the differentiating features between these types of spaces are shown,therebyallowing the characteristic function to offer an overall assessment of the room, which in turnenables the classification of similar sound spaces