Having read him for years now, and seen a few scattered pictures and heard some fleeting words, I just saw Karl Barth on video for the first time in my life thanks to kbarth.org (follow the link to see more videos and a host of other great stuff, compiled by his great grand-daughter).
This reminds me of when, after years of reading Chesterton, I sat in Prof. Sean Davidson's class and heard an audio tape of G.K.'s voice for the first time. It was very surreal at first, but after a while the echoes of that voice start to inform your readings, past and present, bringing to them a new sense of the person, and of their reality.
By the way, Barth's comments in this clip are fantastic insights into his approach to life and work. Based on his answer, the question seems to have been whether he had taken delight in provocation.