Abstract: The purpose of this paper is to describe both method and principle, which applied to the numerical analysis of the sound signal through rock.Based on FFT of recofds, correlation analysis was then used for the calculation of both longitudinal wave and transverse wave velocities. Signal envelope obtained by Hilbert-transform of records was used for calculation of absorption coefficient of rock. The actual application of these numerical procedures are described, and some records obtained using both the "crosshole" field technique and synthetic method show that the suggested procedures are satisfactory to the identification of transverse wave and to the determination of absorption coefficient in rock.