In most conversations, we aren't really listening. We're waiting — loading the reply while the other person is still talking, half-hearing them through the noise of what we want to say next.
It feels like listening. It even looks like it. But the other person can usually tell the difference, because being heard feels nothing like being processed. Plenty of arguments are just two people waiting, not two people listening.
You don't have to agree to listen. You only have to stop composing for a moment and actually take in what's being said. It's rarer than it sounds, and people remember it.