You want to use DocsPlus in the Welsh language. 

Resolution

To do this, first download and install the Welsh synthetic voices from Welsh synthetic voices for text to speech I RNIB | RNIB.  These voices can be used by educational professionals to support learners and by learners on their school and home devices. 

1. Select New Wordbar from the Smart Tab

2. At the bottom left, change the language to Welsh

3. Create a new Wordbar and click go

4. From the Document Tab, create a New Document

5. From the Document Tab click the down arrow next to the Speak Text button

6. Select the Welsh voice.  Depending on your voice install, this may be named Geraint, Gwyneth or Ivona

Tips: 

You do not need to include content in the Wordbar – setting the language in the Wordbar determines the language of DocsPlus’ Predictor and Spell Checker.  The Wordbar can be minimised using the show/hide Wordbar button.