"IBM Develops Virtual Deaf Interpreter":

The technology is meant for use in the real world and could be useful when human interpreters for the deaf are unavailable, or when a conversation is sensitive. Imagine sitting through a lecture and seeing a digital character projected on a screen behind the speaker, interpreting the speech in real time.

...[T]he system, known as SiSi (for "Say It Sign It")... works by using speech recognition to convert a conversation into text. From there, SiSi translates the text into the gestures used in sign language and animates a customizable avatar that carries them out.