I always think of a teacher I had in the 90's who had very strong opinions on the matter and wanted us all to abide by them. He was very soft-spoken but he would raise his voice a bit if we pronounced it wrong: "Day-ta is a name, dah-ta is information!"

The other time he raised his voice was to yell at a student, "Fire is not an element!!!" (we were talking about the periodic table at the time)