The daughter of Sir Percy won at Brighton on her penultimate start and was second to decent filly at Nottingham last time out.
As is often the case at Folkestone, the field set off at a frantic early gallop with Neil Callan settling Sound Hearts in the midfield.
The leader, Cochabamba, kicked off the turn going three lenghts clear. However, Sound Hearts went in pursuit, responding well to Neil's urgings.
She took over the lead inside the final furlong, wearing down Cochabamba to win by length and a half.
Roger said: "Sounds Hearts in a gutsy filly who takes her racing very well. She is improving and deserved this second win."