If you have purchased additional VST instruments from Steinberg and would like to use them in Dorico or even set them as your default instrument choice for playback then please download the appropriate playback template. For details on how to use the playback template...

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,...