I have a "ding!" bell and use it quite a lot, but people react very differently. Adults on their own, and children for some reason, tend to get it, they look up and move to one side. While some elderly people look like they're about to have a heart attack or jump into the bushes at the sound of a bell, so I'm a bit wary of using it behind them just a warning.

And mothers with loose toddlers will sometimes go berserk too at the sound of a bell. I have children myself so I try to make a point out of slowing down and giving the child a huge friendly smile... "see, I'm nice, I'm NOT an ogre about to run you into the asphalt just because your mother says so!"