I have a wildlife tech caller I have never tried on pigs works great on everything else. For pigs the best foolproof way is to set up a tripod feeder. Just make sure you anchor the legs. Fill with corn and give it some time. Once they find it your all set.
You will need to secure the stands with stakes in the ground or putting them in cement. Around here, the hogs have learned that if they can eat out of the Boss Buck feeders by standing on their back legs and by raising up under the feeder and bumping their snouts on the bottom of the feeder to knock corn out. They can empty a 300lb feeder in one night.
Feeder legs in concrete and stakes in the ground won't do anything to stop a bear.