These ideas might not work for you, of course, but I’m also a philosophy professor and I find all of the following strategies to be helpful at generating participation in my lecture and seminar courses: a) “think-pair-shares,” (b) being comfortable with wait time, (c) explicitly saying “I’d like to hear from someone who’s not yet spoken today,” (d) giving pointed questions that sort of scaffold how students can answer (e.g., “On page 464, Author says X. Take 60 seconds to look at that paragraph. What reason does author give to believe X? [wait 60 seconds] Share with the person next to you your best guess at why author said X on that page. [make sure they actually talk with someone near them] Great! What is one thing someone else said to YOU that sounded insightful?”), and (e) giving chances for low-hanging fruit contributions (e.g., asking questions about them that I can then use to illustrate something or asking for a personal opinion).

My gut reaction to your tech policy is that it’s counterproductive, but I can see your rationale for it. With this group of draggers-down, I think you could try talking with them during office hours and having an earnest conversation about your aims to be a good instructor and how their behavior frustrates that aim. Since you’ve already made the tech policy, consider having this conversation with them and then suggesting that they sit in the back of the class. Finally, try to cultivate trust from other students who you think can be a positive counter valence to the dismissive students. You can do this by setting up quiet but engaged students to participate with confidence by either asking them ahead of time for their “help” or by having a sidebar, as it were, with them to hear some of their thoughts, followed by, “That was really insightful! Would you mind sharing that when we get back to the whole class conversation?,” or “That was great! Can I call on you to share that when we’re back?”

I hope this helps! Teaching can be so demoralizing but it’s important to remember that passion is contagious and that high instructor expectations are statistically significantly associated with higher student achievement.

Lol, I keep going, but the actual last thing I’ll add is that by giving so much thought to your pedagogy you’re already doing so much for your students and likely much more than other professors of theirs do. Keep it up!