Christiana McMahon does not peer into a crystal ball or wear a scarf around her head, but she does hear, see, and feel what others cannot, she said, and shares the information via Skype and cellphone with an international client base. Ms. McMahon, who lives in Southampton, has had telepathic skills, including the ability to channel the spirits of those who have died, since she was born, she said, and has been using them full time as a professional intuitive consultant and medium for 10 years.