What causes annoying hacking coughs?

For a year my father has developed a hacking cough that is very annoying and I would like to know if this is the start of something serious or is it something that will go away on it's own? The times that Dad gets this annoying cough is when he eats foods like hot dogs and then he will start gagging and hacking. Even talking causes my Dad to cough and he can't sing either due to the cough. Dad doesn't smoke but Mom and I have even talked him to go to the doctor but Dad insists that he's fine. Could my dad need his tonsils removed or could it be the sign of a sore throat or hernia?