Inclusion Criteria:  Age ≥ 18 years old Patient with a scheduled surgery for a cancer (suspected or declared) with a classic or ambulatory hospitalization Patients requiring general anesthesia with or without associated loco-regional anesthesia or loco-regional anesthesia alone Patient with a smartphone or a tablet or a computer and able to install the application Inclusion of the patient minimum 7 days before the date of the surgery Patient who signed the informed consent Patient affiliated to a French social security system  Exclusion Criteria:  Emergency surgery Plastic surgery for reconstruction: lipomodelling Prophylactic surgery: no suspected or existing cancer Bradycardia (< 50 beats/minute) with β-blockers Severe heart failure with ventricular ejection fraction < 40% Uncontrolled chronic pain for more than three months on morphine Patient with unstable epilepsy or respiratory pathology with rest dyspnea Patient used to and having a regular and habitual practice of relaxation techniques such as yoga, hypnosis, sophrology, meditation, music therapy, virtual reality, ... Medical (neurological, psychiatric, etc.) or psychological conditions not allow for participation in the protocol (completion of questionnaires and booklet, compliance with the cardiac coherence program coupled with hypnosis) Deaf patient without hearing aids Patient under guardianship or curatorship