Consider this line from Walt Whitman's poem Leaves of Grass: "I sound my barbaric yawp over the roofs of the world."
Francis Su, Harvey Mudd mathematician, claims that Whitman's "yawp" was "an inner groaning inside each of us, too deep for words, that is yearning to be expressed and experienced."
In contrast, star teacher John Keating, in the movie Dead Poets Society, suggests that a "yawp" is a "loud cry or yell."
So, Su puts the two together, claiming we should encourage students to have "mathematical yawps," symptomatic of loudly expressing our inner appreciations for an elegant proof, surprising discovery, or beautiful mathematical idea.
So, let's start hearing those mathematical yawps...and why not start with teachers themselves!