We’ve all had experiences where time seemed to stop; we thought we had lived a minute when only 5 or 10 seconds had passed. Adrenaline will do that.
This also happens when speaking to an audience. You ask a question, pause to allow time for the audience to process the question, and then you continue; when you review a recording of the presentation, you discover that the pause you provided was barely long enough for a breath of air let alone sufficient time to process your question. A key component of your message may have been lost through your haste to deliver the answer.
Practice pauses with a digital clock; practice until the pauses are like words in your speech. If you will be using a lectern, take the digital clock with you. A technique I use is “1 Mississippi, 2 Mississippi…”, a “Mississippi for each second, but instead of mentally saying “Mississippi” I mentally spell “M-i-s-s-i-s-s-i-p-p-i”; even on adrenaline-time, this is about a second per “Mississippi”.
Pauses for story enhancement should include some “mime action” during the pause to bring more drama to the scene: peek around the wall or open the door.
The Pause is one of the most powerful tools in your speaking arsenal. Ensure they are long enough and poignant enough for the situation you are crafting.