I want to borrow his idea and suggest a "drill" for becoming a better listener. It also involves developing patience and humility. Here it is: consciously determine that for a day, week, or month, that whenever you are part of a conversation, you will say less than anyone involved. This may not be difficult with certain, very talkative friends, but in order to accomplish it around people who say very little, you will have to get in the habit if asking good questions. If you are a teacher like me, it will mean finding creative ways to get people to enter and lead discussions. Now, someone might say "that is easy, I just won't say anything." But f or the purposes of this experiment, I think it is fair to say that you aren't actually part of a conversation if you don't contribute.
In case you are wondering, this is something that I am going to be trying for myself as well. I need to learn to be a better listener (as well as more humble an patient). If you try it out, let me know how it goes. My hope is that it will develop into a lifestyle. Not that there aren't times when it is necessary to say more--I am a teacher, speaker, writer--but in general, it would almost certainly be a great virtue to develop.