An individual Joe Smith with a PhD would be addressed as Dr Smith or Joe Smith, PhD but not Dr Joe Smith, PhD.
It's called getting your PhD.
Malcolm X: University of California Berkeley"What do you call a blackman with a Bachelors, Master's, or PHD?..You call him a N####r..."
Professor or Scientist. Sometimes (If they have a doctorate or a PhD) you can call them Doctor.
Someone who has earned their PhD.
Usually someone wanting to be a university professor has earned their PhD or MFA. If you are working your way toward a Phd you may be a teaching assistant in the meantime.
The standard title for anyone with a PHD is 'Doctor'.
Doctor if they hold a phd or are an MD.
You can call the university, but it seems like they do offer it.
Doctor or the abbreviated Dr. is the title a person receives when they have a PhD
If you are being formal, you can call them, Mr., Mrs., Ms. Miss, etc. Individuals who are pursuing a PhD do not have a title. After they have received their degree, you can then call him/her doctor.
If you call someone, you are the "caller".
You call someone from Omaha an Omahan or for many, call them Omahans