How should a physician address his patients? The patients address the physician? And why one way rather than another? The questions are simple, the answers are not. When Juliet asked, "What's in a name?" she did not realize that the answer might involve cultural anthropology, history, linguistics, and ethics.
Modes of address, and the replies thereto, provide a great deal of sociological information. If we hear a voice, "Oh, Ellen," and then a reply, "Yes, Ma'am?" we perceive a certain status level. If we hear, "Yes, Aunt Jane?" or "Yes, Doctor?" we perceive different levels. Or, if one voice says, "Oh, Mr. Johnson," and another, "Hey, buddy," we note distinctly different levels of respect. Or again, if one voice says, "Good morning, Dr Jones," and another, "Good morning, Doc," we hear a clear variance in deference.
The actual use of names and titles is culturally determined, differing from one country