Abstract: Multidimensional analysis of hydroacoustic data is usually conducted by way of presentation of the signal information decomposed into dimensions of time and frequency using a short term Fourier transform inform of a spectrogram. Same shortfalls of such visual analysis come into place when studying a signal coming from a source changing its distance from the receiver set because of the variations in the signal strength. The proposed method suggests same ways of such normalization scheme that will diminish the influence of these variations by way multiplication of the spectra by a compensation function dependent of time.