When I was riding shared paths, I used to have a little bell, my voice, and an airzound.
The voice is suprisingly quick to deploy, has a range of volumes and offers easy modulation.
The bell is very good at cutting through ear mufflers, conversations, headphones, etc.
The airzound is a traffic to traffic tool.
If the first two didn't work, brakes will be more effective than the third as at least that way you can amble around the obstacle rather than have to negotiate it suddenly leaping 3 foot sideways in shock.
I've only airzounded a ped once. It went something like this:
- Heading through the park, shared path, ped about 120 metres up front, wandering beside the path, hood up, back to me.
- "Hey!" says I, loud enough to alert them. Nothing. 90 metres.
- "Ding!" goes I, no response. 60 metres.
- Should I try the airzound? Hmmm.. Finger hesitates above trigger... 40 metres.
- I'm a bit close to sound it now. Slow down to about 4mph. Prepare to pass.
- Ding! "Ahem!" says I, 10 metres from pedestrian. Last chance.
- 3 metres from ped, he suddenly wanders right, across the path directly in front of my wheel. I grab the brakes, triggering the airzound which is still under my finger. Pedestrian assumes he is about to be killed by a truck and takes a massive dive onto the grass.
Although I think we probably both laughed afterwards, he was actually scared witless at the time. I think if I hadn't stopped he may have gone away with some nasty ideas about cyclists.