It isn't only teenagers that have poor listening skills. The truth is that we all have so much going on in our own minds on the day to day, we sometimes forget to listen to what others have to say.
It is EXTREMELY important to listen. People feel valued when they are listened to. You don't need to take their suggestions, or even agree with them, but you do need to listen.
To show that you've heard try summarizing what the other person said before you respond. If you are unsure that you understand, or you think that the comment was way out to left field don't just brush it off. Instead ask questions. For example, "I'm having trouble following your train of thought, can you explain a bit more?"
Some people have trouble expressing themselves properly through speaking and they need someone with a bit of patience to help them get it out properly. It's worth it in the end though, because they will feel good and YOU will understand better.