Self-Analysis has the solution to this, it shows a person how they can raise their tone level and stop falling towards succumb.

So far, research suggests it may be possible to learn about the tone and pronunciation of a language or even the meaning of words while sleeping, although it is to a weaker level than what we do during the day without noticing.

Sure, this usually applies to tone of voice, level of enthusiasm, and body language, but who’s to say it doesn’t apply to negotiation tactics, too?