It’s interesting to learn that there are new text-to-speech Sapi5 voices, available in regional British variants:
* Welsh voices, Geraint and Gwyneth for text-to-speech as either Welsh-accented English or Welsh. Free, but an email request is required — registered blind people can request the voices directly from the RNIB.
* There are no other free accented voices, such as Cornish or Brummie, so far as I can tell. But as the cost of developing a Sapi5 TTS voice comes down, via automation of the process, and as the systems that drive the voices make them sound less robotic, I foresee a future in which some distinctive British regions and cities develop and offer their own ‘voice’.
There’s also Microsoft Hazel, a very good British voice and better than the previous Microsoft British variants. This voice shipped as standard with Windows 8 and 8.1. The quickest way to tell if a Windows 8 user has it seems to be to install the best genuinely freeware TTS reader for Windows, Balabolka.
If you don’t have Microsoft Hazel you may be able to get it from Windows Control Panel: Language Pack | Add a Language | Select | the wait until you see the “Download is ready…” link appear. (You can apparently also get a free French-accented Sapi5 voice, Hortense, this way. Just download the French language pack for Windows).