This paper focuses on the separation of the smoothing effect of a signal caused by a finite-size transducer and that by an emission source of finite bandwidth. The total output response of a transducer as a receiver is a superposition of these two effects, resulting in a waveform whose frequency response is determined by the product of the spectrum of the excitation, the structure Green’s function and the equivalent spectrum of the transducer’s aperture. The true time function of a source can only be recovered by separating the aperture effect from the detected signal. Results are demonstrated with experimental data determined with capacitive transducers of varying apertures detecting signals on plates of various thicknesses.