Why else would you speak?, you ask. These are some reasons I can think of:
To hear yourself talk.
To blend in.
To shock people.
To get someone else to stop talking.
To break the uncomfortable silence.
People are uncomfortable with silence, and having words fill the air, regardless of their meaning, is more comfortable for most than a silence that sits heavy on your abdomen. And speaking is a great method of getting someone's attention—some people just speak so people will look at them, so they will be in the spotlight. It's not about their words—it's about them. Sometimes you speak to show that you agree, that you're part of the group, that you want the person speaking and the people nodding to be your friends.
But this post is about speaking to be heard. The kind of talking where you actually want the person to understand something, not just hear you speak, the kind of talking that has a mission other than reflecting the same thing everyone else is saying or drawing attention to yourself.
When—or why—would you speak to be heard?
Because you have something to say that matters.
"Italian Gas Horn" by Edvvc - Own work. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Italian_Gas_Horn.JPG#mediaviewer/File:Italian_Gas_Horn.JPG
What about when you don't feel like you have something important to say? Or that what matters to you won't matter to anyone else, so you should just keep your mouth shut? And you've talked yourself down (on the inside) so that it doesn't feel important to say what you think, to contribute your opinion, to give voice to the hurt someone has caused you . . . but you should speak up, if only to feel how liberating it is. And how much it helps you value who you are—because honestly, it takes valuing who you are and what you have to say to make the effort to speak up.
So when you have something that feels important to say, say it! You don't know if it might ring true to someone listening, or help you learn more about yourself or the people around you—or even cause a connection with those people—in the process.