When you take the time to listen to someone, really take the time to listen properly; it shows you value the person, which is the ultimate form of respect. If you look bored or interrupt the person while speaking, you’re showing that you don’t really care what the person has to say.
Listening is a core aspect of leadership; many people in leadership positions don’t listen, they may be hearing, but they are not listening. To become an effective leader, you must close your mouth sometimes and truly listen to your team.
You should never be too busy to listen because it's the ultimate form of respect anyone can give to another human being.