In a medium saucepan, pour in sugar, the vanilla bean and water and cook on medium high heat until sugar is dissolved. Bring to a boil, and allow to boil for about 3 minutes or until syrup thickens slightly. Remove from heat and allow to cool.
Add approximately 2 tablespoons of pure vanilla extract or to taste.
To make soda, put four tablespoons of the simple syrup in a tall glass. Add ice and fill with soda water. Taste, adding more syrup if needed.
You can make crème sodas using just extract. Add another tablespoon of extract to the simple syrup once it cools.