There must be better ways than stuttering to capture the audience's attention during a sermon.
This reminds me of that old time cofC preacher, V.E. Howard, who had a weekly radio broadcast. At least once during his broadcasts, he'd pause and ask, "Are you listening?" My parents listened to his broadcasts, and if we were in the car headed home from my grandparents, there was no escaping the V.E. Howard show.

With five of us in a little VW beetle, we all listened to the same radio shows on car trips. Anyway, it got to the point of listening intently just to try to guess when he'd insert a "are you listening?" comment.
https://www.youtube.com/watch?v=vkBwr0VUb-o At 5:55, you can hear him say, "hear me - are you listening?"
Didn't Charles Stanley used to repeat a phrase during his sermons to get people's attention?? Was it, "listen to me" or something similar??