The episode * Loud As A Whisper*, features a mute alien diplomat who uses sign language. Is the language used in the episode a real Earth sign language, or did they make up an alien language for the episode?
Probably, but surprisingly difficult to verify. All I can find for sure is that Data mostly studied ASL … but I can’t find anything to prove that ASL is what he or Riva used.
http://www.powernet.net/~jcrafton/linguis.html
There’s also this one-line statement, maybe true, maybe not:
http://www.thingswalkingout.com/startrek/tng/2/whisper.html
So, probably ASL, but not 100% certain.
I learned a bit of sign language when I was a kid. IMO, what Data learned wasn’t quite ASL but was certainly derived from it.
Seems like a lot of trouble to go to for the actor. As I recall the guy playing Riva really is deaf.
Not saying it couldn’t be done…just that I would have blown past that during script development.
There are, of course, sign languages other than ASL. Perhaps it was one of those?
I understand French Sign Language uses the middle finger a lot.
Either that or some kind of gesture with both hands held high above one’s head.
I remember reading discussions about this episode on rec.arts.startrek back when it came out.
The language Riva was using was, indeed, ASL. The actor even made up a signing for Ramatis (the star system where Riva was acting as a mediator) consisting of the ASL sign for “R” circling around inside a hemisphere formed by his other hand.
… except for the happy young couple in love walking along the beach by the blue ocean at sunset, of course. 
My copy is boxed up and about 3,000 miles away so I can’t get to it right now but anyone with the The Next Generation Companion at hand can probably tell you for sure as it’s an episode by episode guide to the series with all sorts of background information.
Thanks for the info, folks.
Well, I’ve got my copy of that book right here. To avoid potential copyright violations, I’ll just paraphrase some of the key points.
The actor playing Riva is Howie Seago. According to the book, he actually is deaf, and he was the one who proposed to the show’s producers the idea of an episode built around a deaf character. He was instrumental in changing the original premise of the episode, which initially proposed his character learning to speak literally overnight when a mechanical translater breaks down.
The book doesn’t explicitly say whether or not the Riva character was using ASL in the show. I regret that I cannot offer a definitive answer myself. Even though I’m deaf, I know relatively little sign. The last time I saw the episode was many years ago, and I recall recognizing a few signs, but couldn’t determine for certain if everything was ASL or not.
Being deaf since birth, I was fascinated by this episode when it first aired. It’s one of the few times I’ve ever seen a deaf character handled in a positive light on a TV show in the 1980s, and it’s the only example that leaps to mind of a deaf character existing in an advanced science-fiction universe. I’ve occasionally wondered whether or not Federation medicine would have been advanced enough to eliminate deafness, and hence eliminate the need for sign language. Seems advanced enough to handle damn near everything else. The episode here doesn’t seem to answer that question, since the character of Riva is apparently from a non-Federation world (corrections on that point welcomed, of course). The book describes Riva as a “Ramatisian mediator”, and I don’t know for certain whether that world is really a member of the Federation or not.
Off-topic: You don’t sign, Atreyu? I assume you lip read but how do you communicate yourself if born deaf? Can you talk? I apologize if this comes off as insensitive but I’m just curious.
Thanks for looking that up, by the way. I was hoping someone would when they read it.
No need to apologize. I don’t see your questions as insensitive at all.
To avoid hijacking this thread any further, I’ll respond to your questions via the e-mail address listed in your profile. I hope that will be all right.
Sure. It’s why I have it listed. 
Except male pattern baldness.
IIRC, Data learned several different sign languages from the Enterpise’s computers. Maybe it could have contained elements of all, or sign languages were amalgamated somehow later on in Earth’s history 
Taking your post seriously, I remember reading a plausible explanation for pudginess, baldness, and other defects in the Trek universe – gravitas.
Picard looks very distinctive and commanding with his bald pate and many of the overweight admirals look more foreboding with a little bit of girth around their waists. It’s a conscious choice on their part to keep these “flaws” and could gain the hair back or lose the weight if they wanted to.
Or blindness.
Geordi?
Or was I just whooshed?