Japan’s August 15, 1945 radio broadcast announcing acceptance of the Allied terms was called Gyokuon-hōsō.
The phrase is commonly translated as “Jewel Voice Broadcast.” It was the first time many Japanese people heard Emperor Hirohito’s voice. The recording had been made on August 14 and broadcast at noon Japan Standard Time on August 15.
The emperor did not use the plain modern wording “Japan surrenders.” Instead, he announced that Japan had accepted the terms of the Potsdam Declaration and ordered the nation to endure the unendurable. The formal court language and poor audio quality made the meaning difficult for some listeners to understand immediately.
Gyokuon-hōsō announced the decision, but it did not replace the formal surrender document. Japan’s representatives signed that instrument aboard the USS Missouri on September 2, 1945.