The humanoid people of Ramatis III, whose ruling family has inherited deafness for generations and communicates through a chorus of telepathic interpreters, as seen with the mediator Riva.
The natives of Ramatis III are humanoids outwardly like humans. The members of their ruling line lack the gene needed for hearing, and the condition has been passed down for centuries. Rather than treat it as a weakness, they developed a system in which chosen interpreters are bound to a ruler from birth and speak his thoughts for him.
They are seen in the Next Generation episode Loud as a Whisper. The famous mediator Riva, who helped negotiate treaties between the Federation and the Klingon Empire, travels on the Enterprise with a chorus of three, each voicing a different side of his nature.
When the chorus is killed on Solais V, Riva is left unable to speak for himself. Refusing a mechanical substitute, he decides to stay and teach both warring factions his sign language.