Emperor Hirohito’s radio address announcing Japan’s surrender was commonly called Gyokuon-hōsō.
The term means “Jewel Voice Broadcast,” a respectful expression referring to the emperor’s voice. It was transmitted on 15 August 1945, after Hirohito recorded the Imperial Rescript on the Termination of the War the previous day.
For many Japanese listeners, it was the first time they had heard the emperor speak. The broadcast used formal, classical language and did not plainly say “surrender” in the everyday sense. Instead, Hirohito announced that Japan had accepted the Allied terms and would end the war.
The recording was made during intense political tension. Officers opposed to surrender attempted a coup in the early hours of 15 August, but the recording was preserved and broadcast. The address announced Japan’s decision; the legal surrender was signed aboard USS Missouri on 2 September.