Technical aspects of television subtitling in the education of the deaf

This paper describes the research and development which has led to the design of a modular low-cost, high-quality subtitling system based predominantly upon widely available consumer components and intended to produce open or closed captions on standard video cassette recorders.The only non-standard components of the system are a special-purpose video display mixer for combining text and picture information, and a suite of software which fully supports the subtitle preparation process. The software is menu-based for use by inexperienced users and allows any user who can type to produce high-quality teletext format subtitles. The display mixer can be upgraded to provide facilities for downloading broadcast subtitles, teletext pages and telesoftware. Four prototype units have been built and have undergone extensive evaluation in schools for the deaf and partially hearing units. Feedback from the evaluation has resulted in a finalised design which should be available commercially in 1986.