In all the classes I've had there are oral components in most or all modules of the course. For most of the major exams there are passwords that you have to get after completing the oral component, which is basically a mini test over the phone to make sure you understand what you've been learning.
So, to answer your question simply, there are 'tests' over the phone as well as quizzes and exams.
So, to answer your question simply, there are 'tests' over the phone as well as quizzes and exams.