Louder silence - taken from 1 of the super stories in "Bending the Landscape: SF"
Era: Any
Location: Planetary (or ship)
Series Type: Any
This is more of an alien idea, but you could tie it into any other current planet-based adventure with interesting effects toward the resolution prospects.
A planet where it's avian-like (and still flight-capable) race have extraordinarily powerful voices - enough to shatter crystal, and to permanently deafen the ears of lesser species such as humans (and do worse to Vulcans and Ferengi). They are a wonderfully ritualistic society, and their crystal-rich home includes many valuable items.
Those coming to this world receive deafening implants - basically, a way to block the ear canal so that the soundwave/vibrations don't smack the cochlea to heck and back, and as such are limited to textual or sign communication.
The Federation ambassador here at the moment could even be Riva (?), from the episode "Loud as a Whisper," from TNG. Telepaths would also do well here.
With all manner of large predatory animals on the world, and the avian race just new to warp travel, things could get interesting, to say the least, if other races came to negotiate with the aliens - but had to be limited to such frustrating (to them) forms of communication.
Michael Barratt
So you think, 'Might as well,
Dance a Tango to Hell,
at least I'll have Tangoed at all.'
-- "Rent," Jonathan Larson