The Nuremberg trials were an early experiment in simultaneous translation. The charter of the International Military Tribunal stated that the defendants had the right to a fair trial and that, accordingly, all proceedings be translated into a language that the defendants understood. Each of the four international judges also had to understand the proceedings. The U.S. company IBM developed a translation system based upon an earlier translation system it had installed at the League of Nations in 1931. In this earlier system, speeches were pre-translated and then read simultaneously in the various languages.

At the Nuremberg tribunal, five translation channels were used. The first channel contained the verbatim transmission of the speaker. The other channels were translations in English, Russian, French, and German. Each participant in the trial had a set of headphones. There were six microphones placed in the courtroom -- one for each judge, the witness stand, and the speaker's podium. Three teams of interpreters worked under the direction of U.S. Army Lieutenant Colonel Leon Dostert and U.S. Navy Lieutenant Commander Alfred Steer. Two teams would alternate shifts in the courtroom, while a third team on standby sat in another room listening to the proceedings. A fourth team of auxiliary translators was on hand for other languages such as Polish and Yiddish, and two other interpreters sat on a bench behind the judges.