The case with that is Jas is really "whispering" the thought-speech, they would have to be within about three feet to hear it. The reason I don't post things like this is because Jas doesn't really have any knowledge about thought-speech. He's just doing what comes natural to him. He would normally be whispering in this situation, so he naturally whispers in thought-speech. But if your character is able to sense it, perhaps your character could tell. I don't know your abilities, but I doubt the others would even be aware of the thought unless they have special abilities.