Why do i cough when i eat?

About a week ago, i started to cough while eating. I'd eat a sandwich and during chewing, i start to cough my food out of my mouth, as well as exhale sharply/shortly. These coughs aren't like the normal coughs, their like short, quick, heavy coughs that occur multiple times within a 10 second range. This only happens during eating, but nothing else. It bugs me a lot at the dinner table with family around. Please help?