EN IEC 62731:2018 pdf free download
EN IEC 62731:2018 pdf free download.Text-to-speech for television – General requirements
6.2 Functionality: TTS device/engine
The functionality requirements for the TTS device/engine are:
• an external TTS device should be designed to be fully accessible to visually impaired users without being dependent on the TV;
• the volume level of the TTS device/engine shall be changeable by the user: the TTS device shall announce the new volume level; it should be possible to do this independently of the TV volume;
• the user should be able to adjust speech characteristics like speed, pitch, voice type, when applicable;
• the TTS engine should announce abbreviations in a manner suited to the context, for example: “IEC” should be announced “I E C”; and “IEEE” should be announced “I triple E”.
• The TTS engine may also pronounce common acronyms in full, e.g. “sub” could be spoken as “subtitles” where appropriate;
• the TTS engine should announce numbers in a manner suited to the context, e.g. as a natural number, digit-by-digit, etc.;
• the TTS engine should announce proper nouns (e.g. names, place names) correctly;
• levels of announcement quality are at the discretion of the implementers; the following are examples of the implementation in order to achieve good levels of quality:
– consider ways to update the vocabulary database and conversion rules of the TTS engine;
– consider provision of additional information (= metadata) to help the TTS engine for pronunciations or readings;
– consider ways in which device users can provide service providers with feedback on incorrectly announced terms.
6.3 Functionality: TV
The TV determines the user interface, i.e. what is displayed on the screen, and how the TV interacts with the user. The TV therefore also determines which text is sent to the TTS engine.
The TV can receive updated words, associated conversions and updated conversion rules for the TTS engine via a network connection.
The user should be able to control, via the TV TTS, settings such as volume, speed, pitch,voice type.