Acoustic emission nondestructive testing method is very widespread diagnostic method based on phenomena of radiation of acoustic waves during the materials destruction. The main advantages of the method are sensitivity to the crack and possibility of remote testing when sensor installed far from the defect. The main drawback of the method is complexity of data processing. Acoustic emission signals are characterized by the variability of the shape and spectrum associated with the dispersive nature of the propagation of the signal along the waveguide. Uncertainty of the signal waveform and spectrum complicates the development of the data processing methods. The article proposes an empirical model of the acoustic emission impulse constructed using generalization of experimental data. The use of this model makes it possible to increase the efficiency of noise filtering by comparing the shape and spectrum of acoustic emission impulses and noise at various distances between the defect and the sensor