EFFICIENT METHOD FOR PRODUCING OFF-LINE CLOSED CAPTIONS

Disclosed is a five-step process for producing closed captions for a television program, subtitles for a movie or other uses for time-aligned transcripts. An operator transcribes the audio track while listening to the recorded material. The system helps him/her to work efficiently and produce precisely aligned captions. The first step consists of identifying the portions of the input audio that contain spoken text. Only the spoken parts are further processed by the invention system. The other parts may be used to generate non-spoken captions. The second step controls the rate of speech depending on how fast the operator types. While the operator types, the third module records the time the words were typed in. This provides a rough time alignment for the transcribed text. Then the fourth module realigns precisely the transcribed text on the audio track. A final module segments the transcribed text into captions, based on acoustic clues and natural language constraints. Further, the speech rate-control component of the system may be used in other systems where transcripts are required to be generated from spoken audio.