*UPDATE* I would add this to the GitHub but I'm not quite sure how to GitHub confuses me with all its jargon I have yet to sit down and learn it.
ISSUE:
The PIPER voices are great! And add like thousand new choices. but, changing Speed in Read Aloud Extension, Even 1 click < or >, changed the hfc_female_voice[medium] ENGLISH voice and pitch completely to different voice? its great but slightly too fast for me.
not sure why ppl are giving bad reviews for " synthesized voices" maybe they didn't log in to create an account or didnt give permissions in ignorance. SHAME!🔔..lol.
They're much better than English Google Translate.
A fantastic app extension and I use it multiple times a day changing from 4 to 5 star

Thank you for , what I can only imagine, is extremely hard work...FREE of charge, to bring the masses a fantastic extension. so much better than the stock windows voices. Alas, ppl still complain & talk smack.
(Using Latest Windows 10 64bit Desktop W/ Regular Firefox Install).
I also use it on Android now, and it works just as good haven't checked out the PIPER yet on that.
Thanks Again!