There's body language and then there's growling....

Growling would be a sound. Reading their body language and acting accordingly based off that, so long as it produces no sound, is coatally fine with me. Then again, it's fine with me even if you did produce sound.  

By the way, it's worth noting that keeping track of everybody's "word count" would be on an honor system.  Just periodically mention in your posts what your character's number is. It's entirely unreasonable that either the player or GM would  be expected to physically count every word (especially considering a lot of those words are probably from histories). >,>