It’s good to start with speaking and listening (and you should always try to avoid the temptation to use silent writing as a management weapon). But don’t just ask a question and expect an answer. Allow a minute or two (literally - time it with your watch) of silent jotting first. Now everyone can speak, because they have written something down; you aren’t left dependent on volunteers, and no one can opt out if asked, because you can say, ‘Just tell us what you’ve written down...’.