"I'm interested in hearing your thoughts on air horns?"


just guessing, but they would probably work on bears that hadn't heard them before.  once exposed and no real harm done, a persistant bear would likely ignore the airhorn, just like they do with banging pots together. 

for a predatory attack, I'd say they might work, or not - but consider that the bear in the second incident was sprayed four times at close range with pepper spray, and was not totally deterred from pursuing his attack

airhorn would be a lot cheaper than a can of pepper spray, but if it was carrying one or the other, I'd go with the pepper - might be a cheap backup to try to scare nuisance bears away