According to information I found on the website of Puddle Dancer Press, this recording was made during an International Intensive Training in nonviolent communications, held in 2000 in Corona, near Los Angeles.
When observing that in difference to the other recordings from the Corona 2000 set, there is no interaction with participants here, I doubt this. I think Marshall made this recording at a different time.
Content by PuddleDancer Press.
Use of content okay with attribution.
Please visit www.nonviolentcommunication.com to learn more about Nonviolent Communication.