Gyokuon-hoso is the Japanese name for Emperor Hirohito's 1945 radio broadcast announcing surrender.
The term translates roughly as “broadcast of the jeweled voice,” a respectful reference to the Emperor's voice. Hirohito's recording was made on August 14 and broadcast at noon Japan Standard Time on August 15, 1945. It was the first time most Japanese people had heard the Emperor speak.
The recording used formal court language, so many listeners did not immediately understand that it announced defeat and acceptance of the Potsdam Declaration. Hirohito avoided the direct word “surrender” in the broadcast, describing instead the acceptance of the Allied terms.
A group of military officers attempted to prevent the recording from being broadcast in the Kyujo Incident, but the recording survived and was transmitted. Gyokuon-hoso is therefore both a communications milestone and a symbol of the end of Imperial Japan's wartime mobilization.