Hearing voices is probably the worst form of acoustic hallucinations; which can be experienced as severely disturbing and is influenced by diverse factors including the ability of the individual to influence and control the hallucinatory experience itself. In recent years virtual reality has become a treatment option. In the so-called AVATAR Therapy, patients with schizophrenia and acoustic hallucinations design a visual and auditory recreation (avatar) of the entity to which they attribute their hallucinations. Working with a therapist over the course of several sessions, participants change the avatar from controlling to benevolent. Avatar Therapy involves similar processes to learning and cognitive restructuring, comparable to other psychotherapeutic interventions. The investigators plan to conduct an interventional study using a cross-over design, to compare the feasibility and efficacy of virtual reality avatar therapy for patients with acoustic hallucinations (independent of psychiatric diagnosis) with a cognitive behavioural group therapy aimed to improve social competence.