Top panel: five-day average of the phase shift for the artificial case illustrated in Fig. 3. The red contour delimits the region where the phase shift exceeds 0.085 rads. The strength of the acoustic source is shown in the bottom left corner. Bottom panel: probability map of the artificial active region illustrated in Fig. 3, as retrieved from the application of the neural network. The integrated probability P_i of the feature inside the blue circle is shown in the bottom left corner. In both panels the blue circle is centered at the location of the acoustic source, with a diameter of three times its FWHM.