The 1945 radio address announcing Japan’s surrender is called the Gyokuon-hōsō in Japanese history.
The term is commonly translated as “Jewel Voice Broadcast,” referring to the emperor’s voice. Emperor Hirohito’s recorded message aired at noon on August 15, 1945, and told the Japanese public that the government had accepted the Allied terms in the Potsdam Declaration.
The broadcast was carefully prepared because Japan had no tradition of the emperor addressing the population directly by radio. Hirohito spoke in formal Classical Japanese, and many listeners did not immediately understand that his words meant Japan had accepted defeat. The recording itself was also faint and distorted.
Hard-line military officers attempted to prevent the broadcast during the Kyūjō incident, a failed coup in the Imperial Palace. The recording survived and reached the national radio network, making the address one of the defining moments of V-J Day.