Originally Posted By: Pete
... Why exactly do you need a whistle? The chances are, if you have an emergency in an urban area, then you can just call for help. The main reason why you might not want to do that - is because SOME of the people in your area are NOT friendly. In which case, a whistle isn't much help. ...


A whistle, in an urban setting, is a very effective signaling device. However, it is not specifically for summoning HELP, it is for summoning ATTENTION. This is why traffic cops and crossing guards routinely use them. I have effectively used a whistle in urban emergencies to stop traffic, help control crowds and to alert pedestrians to danger.