A man went to hit me with a stick the other day cause I scared him and his reflex was to use the stick. He had a dog, he was about 40 years old, it was day time and he was holding a fairly long stick. I think I had more right to be scared...
A loud cough often alerts people earlier than just sneaking up on them - but then again it might give a grumpy old git time to swing his stick harder ;-)
just fart loudly before passing them.