In learning any new language, you have to figure out where to begin. That is also true for learning the language of listening.
If you belong to the "I'm the Smartest Guy in the Room" club or feel obliged to explain why everyone else is wrong, then listening is probably a foreign language to you.
Unfortunately, there isn't a RosettaStone tape to learn to listen. You have to learn on your own, often cold turkey.
Here are some suggestions for where to start:
Watch Good Listeners
Just as some people learn a new language by watching TV shows in that language, you can learn a lot about listening by watching good listeners. You may not have to go very far to find them. They may be coworkers or your employees. Put them in charge of a brainstorming session and see how they guide a conversation and listen.