[Emacspeak] Changing voice with swiftmac

[Tiresias <isaac.m.j.s.leonard@xxxxxxxxx>]

Hi All
A few weeks ago I attempted to change the voice I was using for the swiftmac server and thought it went well.
I had been using the Karen Enhanced Australian voice for as long as I’d been using emacs however I was having issues with it and attempted to change to the Alex American voice.
I downloaded it and changed the voice to Alex in my init.el with the following code as suggested in the swiftmac readme:
  (setopt swiftmac-default-voice-string "[{voice :Alex}] [[pitch 1]]”)

This seemed to work well and changed the voice however I cannot seem to change it to anything else now including Karen or other voices I download.
Does anyone know what I need to do to make it work?
I use to set the Karen voice with the following line however it now seems to do nothing:
  (setopt swiftmac-default-voice-string "[{voice Karen-premium}] “)
Or:
  (setopt mac-default-voice-string "[{voice Karen-premium}] “) 

Best regards, Isaac