Why do pedestrians listen out for cars and when they hear no engine just cross the road without looking?
When you ring a bell some pedestrians look up in the air????
Don't you need an Airzound? http://www.youtube.com/watch?v=RuEMvJ4y9y4&NR=1
I use an air activated warning system. It has multiple warning sounds, varying between 'Excuse me, mate' at one end of the range and 'Get out of the f*cking way' at the other. Much more effective than a bell and lighter and cheaper too.