I enabled Narration in Guides from this link:

https://docs.microsoft.com/en-us/dynamics365/mixed-reality/guides/operator-narrator#turn-narration-on-or-off

This works great but the narrator's voice sounds like Microsoft Sam from Windows XP maybe from 2005-2009.

Would it be possible to use Cortana speech engine to narrate, instead of the older offline speech synthesis?

I love to hear Cortana's voice!