For each pre-recorded synchronised time-based media that has subtitles, can these be vocalised (excluding special cases)?

Tests

1. 4.18.1

   Does every pre-recorded synchronised time-based media with subtitles meet one of these conditions (excluding special cases)?

   A sound track containing a vocalisation of all the subtitles can be activated by the user.
   An available feature that allows subtitles to be vocalised.
   The subtitles can be vocalised by assistive technologies.
   An alternative version is available, with all the subtitles vocalised, accessible via an adjacent link or button.