These are individual Voice files. They usually tweak existing internal sounds (changing effects, EQ, or filters).
Download Yamaha PSR-S970 Voices – Expansions, Presets & User Content yamaha psr-s970 voices download
The Yamaha PSR-S970 remains a powerhouse in the arranger workstation world, largely due to its expandable sound engine. While the factory presets are world-class, downloading and installing new voices is the best way to keep your keyboard feeling modern and tailored to your specific musical style. These are individual Voice files