The recorded imperial broadcast announcing Japan’s acceptance of the Potsdam Declaration was called the Gyokuon-hōsō.
The broadcast aired at noon on August 15, 1945, with Emperor Hirohito reading the Imperial Rescript on the Termination of the War. It was recorded on phonograph discs inside the Imperial Palace the previous day and transmitted by NHK.
Gyokuon-hōsō is often translated as “Jewel Voice Broadcast,” referring honorifically to the emperor’s voice. The term describes the broadcast rather than the surrender document itself. Hirohito did not use a simple conversational style: he spoke in formal Classical Japanese, which many listeners found difficult to understand.
The announcement followed the atomic bombings of Hiroshima and Nagasaki, the Soviet Union’s entry into the war against Japan, and a failed military coup attempt intended to prevent the recording from being aired. For many Japanese listeners, it was also the first time they had heard the emperor’s voice.