The complete recordings of the Nuremberg War Crimes trials are online. The International Court of Justice in The Hague, Netherlands, the custodian of the original materials, arranged the digitization of its archive, collaborating with the U.S. Holocaust Memorial Museum in Washington and the Mémorial de la Shoah in Paris. There are 775 hours of recordings so this is not for the casual listener.
Edward Rothstein writing in The Wall Street Journal explains that the recordings aren’t easy to listen to in part because the recordings do not translate the German, English, French and Russian spoken at the trial. Even so, Rothstein concludes that:
what is heard, even now, seems remarkable: a rough first draft of judgment, beginning just five months after the war with Germany ended and unfolding over nearly a year as its arbiters strained to fit minimal forms of existing law to maximal forms of moral degradation.