Falling Whistles
Falling Whistles sells whistles for $34 to $104 to raise money for education, advocacy, and the rehabilitation of war-affected people in Congo. The organization got its name from a journal written by its founder, sharing his experiences during a trip to eastern Congo in 2008. During that trip, Falling Whistles' founder met a group of five former child soldiers who told him that some children who were too young to carry weapons were sent into battle armed only with whistles. By wearing whistles, the campaign aims to use this weapon as a tool of protest and to raise awareness of the situation in Congo. As of September 2010, $500,000 has been raised.
Train whistle
Two-note and four-note train whistles never caught on with North American railroads, with one exception: Canadian National Railway created a large four-chime step-top whistle for limited use on some of their locomotives. These were not common and only a few survive today in the hands of collectors. Otherwise, North American train whistles were of the single-note, three-note, five-note and six-note varieties.