How does the Judge's Ear work?

The character can recognize as lies all deliberate lies presented to her. The character can also recognize the deliberate use of half-truths, though doing so does not tell her which part of the statement is true.

Recognizing deliberate lies and deliberate half-truths makes me think telepathy/ psionic type powers, but with that name it could be subsonic cues and the like. Or it could be other stress signals. Or it could be analysis of the physical reactions in the brain.

The power type makes a huge difference about how well it'll work on this telepath here.