There seems to be some ways to do it in linux, but haven't tried myself yet: https://askubuntu.com/questions/953509/how-can-i-change-the-voice-used-by-firefox-r

There seems to be some ways to do it in linux, but haven't tried myself yet: https://askubuntu.com/questions/953509/how-can-i-change-the-voice-used-by-firefox-reader-view-narrator-in-ubuntu https://askubuntu.com/questions/953509/how-can-i-change-the-... I'm not super fond of having to run any particular background service for this.