One of the dirty secrets of public speaking is that audiences don’t remember much of what you say. I’ve seen a range of studies over the years showing retention of anywhere from 10 to 30 percent of what an audience hears.

Many, many efforts have been made to increase that percentage. Microsoft funded some studies hoping to find out that the judicious use of PowerPoint increased retention.

It didn’t.

Multi-tasking reduces retention, and listening to a speaker while watching a set of slides is multitasking.

The US Army tried repetition. That’s where the “tell ‘em what you’re going to say, tell ‘em, and tell ‘em what you said” came from – the idea that if you repeat something three times it increases retention.

It doesn’t.

At least, not enough to make it worthwhile, given that some significant percentage of your audience is going to be annoyed with the repetition. Especially in the era of smart phones, when the audience is itching to check their messages if they’ve been good and stayed off the things for nearly an hour.

Many speakers try handouts, printed visuals, summaries, and so on – memory aids of a physical nature.

That’s no help either.

If you watch the behavior of audience members at conferences, 80 percent throw the handouts away on the way out the door. Spare the trees.

Other speakers and conferences create virtual versions of handouts. There were CDs and then USB drives once upon a time. Now they look quaint. Why not just put the information on a website?

Because then you’re losing the main point. You’re not making the speech more memorable, you’re just substituting Google for your memory and the memory of your audience.

OK, what to do? There are a couple of smart ways that you can increase retention, and I’ve worked with many speakers to figure out how to amp up their speeches with these methods.

First of all, make sure that your speech is about only one idea. After all, it’s easier to remember one idea than many. And organizing your speech that way is a recognition of how people listen to speeches: they listen to get the gist, to be moved to action, to make an emotional connection. Not to vacuum up ideas like some over-enthusiastic mental Hoover machine.

Second, tell stories. Once again, it’s a recognition of the way people retain things in their minds – by attaching emotion to facts. Stories, in short.

Third, organize your speech in a way that makes sense to the audience, not necessarily to you. If you’re an expert in your field, chances are good you have detailed knowledge organized in a way that is hard for novices to understand. You might have an in-depth awareness of controversies in your line of work, for example, that would simply confuse someone coming to the ideas for the first time. Or your command of detail and fine distinctions might be mind-numbing to anyone who doesn’t care deeply about, say, Irish oracular hand bells.

For audience-friendly organization, start with a problem you know the audience has, and then offer your expertise (a judicious amount of it) as the solution to that problem. So, for example, your audience doesn’t care about the tensile strength of the higher range of Irish oracular hand bells, but they do care about reducing stress, and it turns out that those hand bells can do just that if played in a soothing manner. So start with the stress and end with the hand bells, and you’ve given the audience a reason to remember them.

And now there’s a study that shows a technique that can increase retention by 76 % in learning that took place over longer periods of time (a month). But the theory is that it will help, even with the relatively short time period of a speech.

Here’s what you do: it’s called interleaving. You get the audience to think about aspects of your talk in different ways. So, you might simply lecture for a bit, then offer another part of your information in an audience interaction, and a third piece in a video.

It turns out that if you mix up the learning styles people remember better. This is not the old audio-visual-kinesthetic distinction. It’s rather the breaking up of what you’re trying to get the audience to remember into pieces, and rather than presenting the pieces all in the same way, mixing up the modes.

Variety feels more confusing at first, but then we retain the information better.

It’s a useful addition to the rather limited arsenal of tools to make public speaking more memorable. Give it a try.