When I grew up, my mom always called us for dinner by whistling. Her whistle was so loud that my brothers and i could hear it a block away at a friends place and know that super was ready. "..gotta go, dinners ready."
It took a little trying to learn how to whistle like she did, with her fingers. Soon after, I learned how to do it without my finders at all and it was equally as lound.
As a cyclist, being able to whistle comes in really handy and has no doubt saved my live on more than one occasion. So, here's my Public Service Announcement on the value of whistling while you bike.
Cyclists can use whistling to
It's free, easy, fun to learn and it might save your life.