I'm slowly figuring out that these types of non-interactive, live presentations are unnecessary.
If I'm going to listen a someone speak without me being able to respond/interact/have a conversation with them, it can be recorded and I can watch it whenever is convenient for me.
I feel this way with work presentations too -- record them, and let me watch them anytime. Don't make me sit and listen to someone (or a group of people) give a lecture, so that I have to follow along live.
If I'm watching a recording, there's a far greater chance that I'll actually absorb the content, as a) it'll be during a time that works for me, not some arbitrary scheduled time that may or may not interrupt other things that are distracting me from the presentation, b) I'll be able to rewind if -- no, when -- I zone out for a minute, and c) I can skip/speed up the parts that aren't as relevant to me.
I wish we would move away from these live lectures/presentations, and more to async/recorded sessions.
(As a bonus, it also makes the speaking/presenting side easier, as it can be edited, if desired.)