A handful of summers ago, I spent a couple months as a volunteer teacher in Papua New Guinea (PNG). While there, our team discovered an incredible hesitancy for students to speak-up during class time, and when they did, it was barely louder than a whisper. I suspect there are some good reasons for this: English--the language of instruction--is the second (or third) language students learn; moreover, a number of cultural norms seem to encourage students to remain quiet. To combat this, I did an activity where I had my class simultaneous shout the answers to various questions.
In the American University, there also appears to be influences that discourage students from asking questions. Perhaps the most common one being the fear of asking a bad (i.e. 'stupid') question. This post is my attempt to combat it.
The irony is that instructors crave for students to ask questions--even the 'bad' ones--because they reveal what aspects of the lecture the students are understanding and what ideas haven't been communicated effectively yet. But this is precisely what the student is afraid of: that by asking a question they will reveal how much they don't know (i.e. how lost they are).
Of course, being a student is all about not knowing (that's why one is taking the course in the first place). When one signs up and attends a calculus course, it automatically signals the instructor that s/he doesn't know the material.
So the fear of asking questions can't be grounded in not knowing, for that's in a student's job description. Rather it seems the fear boils down to the other aspect of being a student: learning. The student may fear that asking questions reveals he/she is an ineffective learner. "If I ask about that, everybody will know I didn't understand it the first time."
A few points to consider: