The 1945 radio announcement in which Emperor Hirohito addressed Japan’s public was called the Gyokuon-hōsō.
The Japanese term is often translated as “Jewel Voice Broadcast.” It refers to Hirohito’s recorded message announcing acceptance of the Potsdam Declaration and Japan’s decision to end the war. The recording was made on August 14, 1945, and broadcast shortly after noon on August 15.
The broadcast was a major break with imperial tradition. Hirohito had not previously spoken directly to ordinary Japanese people on radio, and his voice was unfamiliar to much of the population. His formal language was deliberately indirect, so many listeners did not immediately understand that the speech announced surrender.
Gyokuon-hōsō describes the broadcast itself, not the September 2 signing ceremony. The later ceremony created the legal and diplomatic record of surrender, while the broadcast communicated the decision to Japan’s population.