We chose to have these mounted in a public bathroom rather than a household one to take advantage of the idea of public humiliation. Alone in the stalls, users are allowed to use as much toilet paper as they want, without consequence. Through the use of audio feedback, we essentially shame users that pull too much toilet paper and commend those who do use the recommended amounts.
We based the code on a maximum of 6 squares. With each subsequent pull, that maximum reduces by 1 square until the cap is 2, where it will stay indefinitely. We did this because we understand that each person may simply just need more toilet paper. to finish the job, or blow their nose, wipe off makeup, etc. By reducing the maximum, we are getting users to use less per pull.
If the user remains under the maximum number of squares, the speakers play nature sounds, with birds, bubbling brooks, and the like. As they get closer to the max, the peaceful sounds fade away and become a loud chainsaw, which represents the trees wasted by the user.