Closed-captioning Service by Broadcast News Transcription System Begins

NHK has been working toward the realization of "human-friendly broadcasting" to make broadcasting services available and enjoyable for the elderly and the hearing impaired. One such project involves the expansion of closed-captioned broadcasting. To meet a demand for subtitled news broadcasts, our laboratories developed a broadcast news transcription system that recognizes a newscaster's speech and creates a subtitled script for the news programs. NHK started live closed-captioned broadcasting on March 27 using this system.

Japanese closed-captioning service
This speech recognition system automatically recognizes the newscaster's speech in a studio setting, and creates subtitles. Languages spoken in Europe and the United States use small alphabets, enabling the manual conversion of speech to textual data.
However, with the Japanese language, a proper sentence has to be written by combining appropriately 50 syllabic characters in each of the Hiragana and Katakana forms, in addition to Chinese characters (Kanji), of which several thousand are used in the writing of Japanese. This situation makes manual real-time closed-captioning impossible. Therefore, by utilizing computers, we developed an automated system capable of producing live real-time Japanese subtitles.

Live closed-captioning starts
On the March 27th edition of "News 7," live closed-captioning appeared on the TV screen as a newscaster read a manuscript during the program. This closed-captioning can be utilized by current analog television by means of teletext broadcasting receivers. When digital broadcasting begins, any receiver will be technically equipped to receive the service.