Combine water,sugar and vanilla bean in large sauce pan and bring to boil. Add pears, reduce heat and cook gently until tender (30 minutes). Refrigerate pears and syrup for 24 hours. Remove vanilla bean from syrup. Melt chocolate in heavy pan over low heat, stirring frequently until smooth and glossy.
Scrape vanilla bean pulp into chocolate. Add cream and bring to a boil, stirring constantly. Remove from heat. To serve, place scoop of ice cream in bowl. Place pear alongside ice cream and spoon chocolate sauce over top.