Peter Hess® Sound Massage for Reducing Anxiety and Pain in Cardiac Surgery

* Cardiac surgery patients often undergo anxiousness and pain. Before surgery, anxiety is often caused by the idea of sternotomy, extracorporeal circulation, fear of post-operative pain, and even death. After surgery anxiety and pain can be the consequences of operative and peri-operative procedures. The investigators believe that reducing stress and pain by a relaxation therapy would lead to better stay in hospital and a better recovery after surgery. * Design of the study: Controlled randomized single blind clinical trial / Interventional research protocol implying human being that doesn't involve any health product * Patients will be randomized in one of the two following groups: 1. Peter Hess® sound massage, a relaxation technic using singing bowls' sound vibrations The Peter Hess® sound massage is a holistic relaxation technique (body and mind) that uses sound vibrations generated by therapeutic singing bowls. Its efficiency and adaptability make it a complementary method that can be pertinent for many hospital departments, both for patients and caregivers. 2. Music Care® relaxation technique, a validated Non-Medicinal Intervention which is a pyscho-musical relaxation technique using audio relaxation music diffused in dedicated headphone. The audio relaxing soundtracks are chosen by the patient. Music Care® technique has already proven with several clinical studies its efficiency for reducing pain and anxiety in hospital. * Main Objective: Prove a better efficiency of the Peter Hess® sound massage for reducing anxiety compared to Music Care® relaxation technique. * Main criteria: difference between the two groups on anxiety scores' variation (measured by STAI) between preoperative visit (J-1) and postoperative visit (J+7)