Neural Voices aren't available for me

Hello! I'm using the text to speech function in storyline 360, and I don't have any of the Neural Voice options available in the dropdown. It only has the standard voices. Is there something I'd need to do to trigger storyline to give me the Neural Voices, or is there a version I need to update to? Current version on my company computer is 3.69.28997.0.

Thanks!