I notice that on Sierra, Siri's voice is much superior to the selection of system voices you can select in System Preferences → Accessibility → Speech. In fact, I suspect they use a different system entirely as the command
say -v ? doesn't seem to list any voices which are used with Siri.
I have a key command set up to speak the select text. Is there no way I can get it to use Siri's voice to do it?
Edit: To be specific, I'm after the Siri voice: 'British (Male)'