Empathic listening gets inside another person's frame of reference. You look out through it, you see the world the way they see the world, you understand their paradigm, your understand how they feel.
Empathy is not sympathy. Sympathy is a form of agreement, a form of judgment. And it is sometime the more appropriate emotion and response. But people often feed on sympathy. It makes them dependent. The essence of empathic listening is not that you agree with someone; it's that you fully, deeply, understand that person, emotionally as well as intellectually.