From Knight Ridder News (link):
Chinese instructors are teaching their language to students around the world without ever leaving China, as Liu Yang recently demonstrated while sitting in a cubicle peering at a streaming video image on her computer monitor.
Her headset comfortably on, Liu gently addressed a faraway student struggling to speak in the standard Chinese dialect. She watched him on her screen, corrected his pronunciation and guided him through simple drills in an online textbook.
With the latest technology, student and teacher heard each other clearly. They also saw each other on camera.