The VOIDRUNNER'S CODEX is coming! Explore new worlds, fight oppressive empires, fend off fearsome aliens, and wield deadly psionics with this comprehensive boxed set expansion for 5E and A5E!
I don't think giving rules for that would be sensible. Terrain would make a huge difference, open/closed, half-closed doors... how much noise around...
We did a real world test one time in an empty warehouse... we came up with 60 feet as the range where intelligible communication breaks down without amplification, so that was what we have always used for a practical limit to inspire courage.