Use this blurt alert chart in your classroom to set a daily goal of how many blurts you want your class to try to get less then. Every time you hear a blurt, something that a students shouts out when they are not supposed to, add a tally.
This can be adapted to be used in many ways. You may want to reward your class at the end of the week or day if you chose.
In my class, I have laminated it and every day we try to get lower then the day before. The students love it and will actually correct one another now! It has been a life saver!