It's a different way of getting across an emotion. You're trying to get it across to the animator because the animator is inspired by the voicetrack in terms of how to animate the character.
“Then I sit down, work at it, because now I have a convincing feeling about what that place wants to be, you see? And it's not just me. Me and my talent comes in taking that consensus and then making something wonderful out of it - a work of art.”
“The power of sound to put an audience in a certain psychological state is vastly undervalued. And the more you know about music and harmony, the more you can do with that.”