Emperor Hirohito’s 15 August 1945 radio address was called the Gyokuon-hōsō.
The Japanese term means the “Imperial Rescript on the Termination of the War,” and it is often translated into English as the “Jewel Voice Broadcast.” Hirohito announced that Japan had accepted the terms of the Potsdam Declaration and would end the war.
The broadcast was recorded at the Imperial Palace and transmitted by NHK at noon on 15 August 1945. It was the first time many Japanese people had heard the emperor’s voice. The formal language was difficult for ordinary listeners to understand, so officials and newspapers helped explain its meaning.
The broadcast announced Japan’s decision, but it was not the same event as the later signing of the surrender instrument. That formal ceremony occurred aboard USS Missouri on 2 September. The word “Gyokuon” refers to the emperor’s voice, not to a separate treaty or military operation.