After taking 100+ credit hours at the University of Illinois I have experienced many different classroom atmospheres. To begin with, most entry level undergrad courses range from weed out classes and general ed required courses with class sizes of about 300+ students to upper level major courses with only 15-30 students per section. Clearly, the professors cannot honestly make an attempt to allocate their time to all 300 students during the lecture time, but in the smaller class sizes I feel it is important for each student to feel comfortable with their peers and the professor when it comes to asking for help, working together, and learning.
I hardly ever think it's a good feeling to be left out, unheard, excluded, or singled out in the classroom or other learning environments. I really think that even the changes in tone, mannerisms, or choice of language can make all the difference in a students learning experience.
For example, in both my accounting and business technical writing courses I've experienced group based work and discussion based participation throughout the regular course schedule. One of the most frustrating times as a student is feeling like you're the only person who doesn't understand or constantly has questions in the class when everyone else sort of just gets it or understands the materials.
I had a professor who would sort of rush through the lecture and stop to ask "who doesn't get it?" or "who doesn't understand?" as a way to ask if any students have questions. In this instance, a few students usually have lingering questions but do not raise their hands or say anything because they do not want to feel isolated under the rhetoric of someone who "doesn't get it".
I'm not exactly sure what caused the change, but later in the semester the professor made a point to correct his choice of words when pausing for questions to ask in less isolating way by changing his words to "Do you have any questions?" or "Is there anything you want to go over that might have been unclear?". I would notice 3-4 hands go up (including my own). I feel like that simple change made my entire learning environment more comfortable to ask questions as well as simply participate when I felt I had the right answer or something valuable to say to add in the discussion.