People like what they are used to, and don't see the need for most innovations until they are available in their choice of designer colors.
A device for talking in freefall would have at least 3 uses:
1. Coaching, esp. freefly
2. Audio keys on bigger-way formations
3. Emergencies:
a. "Mike, your bridle is flapping in the wind!"
b. "Bad spot! Breakoff at 6000!"