Terence Tao's homepage has a link to a collection of quotes, and one among them was Hilbert's famous "We must know, we will know" quote. This quote also had an audio link to it. Now although I'm not sure if it is really Hilbert's voice in the link, this prompted me to ask if we could have a collection of (rare) audio/video recordings of mathematicians which are freely available on the internet.
Let me add, however, that I am not asking for audio/video recordings of mathematicians which are fairly recent (a typical example of which I am NOT asking for are TED talks or podcasts). Recordings of famous mathematicians of the early twentieth and mid twentieth century will be wonderful. (I've always wanted to find out how Von Neumann's voice sounded like!).
Addendum: Are there any videos or audio excerpts of any talks given by Grothendieck which are available anywhere? I'd be grateful if anyone could post any such links. Thanks in advance.