I’ve been working recently with clients on more and more 20-minute speeches. As I indicated in an earlier blog post, it’s the era of shorter speeches. Fidel Castro holds forth no more, and Hugo Chavez is gone altogether, so multi-hour practitioners are on the wane, but the rest of us are expected to bring it in under an hour more and more frequently.

My fearless prediction is that 20-minute speeches will become the new norm. I think that’s a mixed blessing. No one ever complained when a speech ran shorter than the allotted time, and we’re all busy, so briefer is better – up to a point.

That point comes when we’re talking about truly changing minds, moving people to action – and changing the world. The problem is the audience, not the speaker’s. Speakers can give good or bad speeches in 20 minutes or in 60. But an attention span lasts roughly 20 minutes, so there’s a different kind of commitment from the audience that happens once the second attention span kicks in.

It takes 20 minutes to lead an audience through a problem to the point where it’s ready to change, to let go of its previous beliefs and take on some new ones. If a speech only lasts 20 minutes, the audience is more likely to listen intellectually, content to try on the idea, without listening with its whole heart. It’s in the second 20 minutes that the real commitment comes – or not.

All of that puts additional pressure on the speaker to jump right in and grab the audience’s hearts and not let go. The only way to do that is to speak authentically, with your true voice. As clients and I have worked, we’ve honed the story and gradually found its true arc, but the real breakthrough comes from two commitments the speaker makes: to authenticity and to voice.

Authenticity comes from being willing to reveal a piece of your life story that matters deeply to you. Then you have to shape it into a structure that people can hear clearly. That’s the art of storytelling, and it’s not simple or easy. The best stories evolve from telling them again and again, so you need to trust the process and let the evolution happen.

Voice comes from speaking with your whole self, your full passion, your entire heart. So many of us learn as we go through life to hide that most passionate part of ourselves, because that attracts criticism, or scorn, or rejection. But that’s precisely where you come alive and have the potential to reach an audience in a deep and unforgettable way. Opening yourself up authentically, finding that Voice, and trusting it to the world – that’s the secret of connection and creating successful 20-minute, world-changing speeches.