Ramatisian
The Ramatisians were a non-aligned humanoid species native to the planet Ramatis III.

History 
Due to a unique heredity condition (see below), members of the ruling line of Ramatis were all deaf. Over the centuries, they developed a means of communicating though the relationship known as a Chorus: a trio who served as translators or interpreters. The ancestors of Riva's chorus provided the same service to Riva's own ancestors. 

Over an unspecified period during the mid-24th century, the Ramatisian mediator Riva mediated several treaties between the Federation and the Klingon Empire.

Physiology 
Much like the Hanovers of Old Earth who suffered from hemophilia, or the leaders of Fendaus V, who had no limbs, the ruling line of Ramatis were also affected by a hereditary condition that caused a missing gene for hearing. With this condition, their brain could not receive auditory information, which meant that their disability could not be augmented with prosthetics or surgical techniques.

As such, a telepathic relationship was formed over a period of years with a "chorus", a trio who "convey not only his thoughts, but his emotional intent as well," a relationship that one such member of this line, Riva, found to be "quite harmonious." With time, the Chorus became so attuned, they could hear Riva's thoughts and translate to those he wished to communicate. For Riva, "they allowed me to combine different perceptions." They also provided Riva with a great deal of confidence.

Riva was also able to perceive that Betazoid Counselor Deanna Troi was herself an empath, but was unable to communicate with him directly. Overall, Troi found his method of communication to be "most elegant and quite beautiful,"  ()

Social norms 
Regarding the Ramatisians social norms, prior to Captain Jean-Luc Picard's first visit to Ramatis III, at the objection of his first officer, William T. Riker, Picard explained that he considered the visit "a ceremonial function" or "a simple ceremonial greeting", rather than an away mission, and that "for me not to go could be construed as lack of interest."  

Upon the away team's arrival, they were greeted by Riva, who offered them food or refreshments, which Picard politely declined. 

When speaking to a member of the ruling line of Ramatis who had a Chorus, it was appropriate to speak only to the individual the Chorus spoke for. Picard made this mistake while speaking to a member of Riva's chorus, rather than to Riva himself, angering Riva. Picard profusely apologized, stating that "the uniqueness of this presentation provoked this inadvertent breach in protocol. No insult was intended." ()

People 
Named
 Riva

Unnamed
 Unnamed Ramatisians
 Riva's chorus

Appendices

Background information 
The name of this species was not mentioned in dialogue, but comes from an internal reference document written around TNG Season 5, later released by Roddenberry Entertainment.  In it, the Ramatisians were regarded plainly as "humanoid, missing gene for hearing". 

The name was also adopted by StarTrek.com, which described in their Klingon article the "Ramatisian mediator Riva."  It was likewise adapted by the  and the Star Trek: The Next Generation - The Continuing Mission (p. 76).

Ramatisian was also the name used on Howie Seago's autograph card, however, according to the Star Trek Customizable Card Game, Riva was a "Ramatin".
Species
Memory Alpha articles named from supplementary resources