[Technical and methodological aspects concerning the application of Fourier's analysis to phonocardiography (author's transl)].

The frequency spectrum analysis (Fourier's analysis) has recently been applied to phonocardiography. Using this mathematical approach instead of the current empirical analysis, it is possible to obtain -- on a less subjective basis -- more precise pathophysiological and diagnostic information from the acoustic cardiac phenomena. On the other hand, this refinement of the method of analysis stresses the need for better technical and methodological solutions, in order to reach the standardization of both the transduction and the recording of the acoustic signal at higher level of sensibility, fidelity and reproducibility. With this in mind, and on the basis of their experience, the Authors suggest the adoption of devices with specific technical characteristics, and propose a suitable method of application of Fourier's analysis to the phonocardiogram.