The choir sounds in Dorico Elements 3.x and Pro 3.x (and later) are the Olympus Choir Micro from Soundiron. If you would like to upgrade or extend those sounds, one option is to purchase the Olympus Choir Elements, which adds extra vowel sounds (Ee, Eh, Ei, Ih, Mm, Oh) and techniques such as true legato and sustain.
Once purchased, you can use those sounds in Dorico by downloading and installing this playback template:
- Olympus Choir Elements.zip (46.5MB, zip, 18th Nov 2021)
In the zip file is the .dorico_pt playback template that will automatically load the samples from this library for each of the singers in your Dorico project, and assign the appropriate expression maps.
For full details, including how to set up a combined playback template for this choir with your existing playback setup in Dorico, see the included documentation in the provided zip file.