Hirohito’s recorded radio announcement accepting Japan’s surrender was called the Gyokuon-hōsō.
The Japanese term is commonly translated as “Jewel Voice Broadcast,” although the literal idea refers to the emperor’s voice. Hirohito’s message was broadcast at noon Japan Standard Time on 15 August 1945. It announced acceptance of the Potsdam Declaration rather than using a simple conversational phrase such as “Japan surrenders.”
The speech was recorded in the Imperial Palace on 14 August. Technicians made two recordings because the first attempt was considered unsatisfactory. During the night, officers opposed to surrender tried to locate and destroy the records in a failed coup attempt. The recordings were hidden and eventually delivered to NHK for transmission.
Many listeners struggled to understand the announcement. Hirohito spoke in formal Classical Japanese, a style unfamiliar to much of the population, and the recording quality was poor. It was also the first known occasion on which ordinary Japanese people heard their emperor’s voice. The formal surrender document was signed more than two weeks later.