A computer-implemented method for evaluating echo signals obtained from a phased array experiment on a billet is disclosed. The computer-implemented method may comprise collecting the echo signals from a pulser/receiver unit, correlating the echo signals with a position on a longitudinal axis and a circumferential angle of the billet, computing an amplitude for each of the echo signals, displaying the amplitudes as indications in a c-scan data plot at a computer display unit, and determining the signal-to-noise ratios of indications located in a region-of-interest box relative to noise in surrounding boxes in the c-scan data plot. The computer-implemented method may further comprise classifying each indication as rejectable, reportable, or insignificant based on its amplitude and signal-to-noise ratio. The computer-implemented method may find applications in quality control evaluations in the aircraft industry.