What can sound tell us that words cannot about the way Brazilians communicate with one another? What roles do things like rising and falling intonation, volume, and enunciation play?

To begin thinking about this, we turn to a speech given by Ulysses Guimarães on April 24, 1984. Brazil was nearing the end of 21 years of military dictatorship, and Guimarães, president of the largest opposition party, had long been among the most vocal foes of the regime's economic policies and attacks on civil liberties and human rights. The next day, the Câmara was set to vote on a constitutional amendment that would restore direct elections for President for the first time since 1960.

Guimarães gave an impassioned speech that was filled with all the rhetorical flourishes that one would expect from a politicians of his age, education, and reputation. Yet as you listen to this clip, pay attention to the way his voice rises and falls, the way he grows louder and then quieter. This is not the way he spoke in interviews, or even necessarily in ordinary speeches. It is the way he spoke when he knew that a nation would be hanging onto his every word, that this speech might well help cement his legacy.