Documentation

While building a lesson, you define its language in the presentation preferences. If you are going to use the Text to Speech addon this is the language in which all speech text are read. This is also the language in which by default all addons are read, however, you can change the language for each addon by defining it in the addon's Lang attribute.

It is also possible to define inside an addon a fragment of text that should be read in a different language. You can define as many such fragments as you want and each one can be read in a different language.

You can use the \alt{text|text}[lang lang_attribute] syntax and "text" will be read in the language defined by the lang_attribute.

In the documentation of the Text to Speech addon in the section Languages, there is a script that checks what languages are available to you on your browser. You can add more languages by adding them in your operating system.