Matching the voice in difficult situations is a little like verbal aikido. There are two different ways that martial arts are sometimes categorised – hard and soft martial arts.
Hard martial arts use more strength and power whereas soft martial arts are more about how you channel the energy in movements. So in Karate, you would use more strength and power to block a punch, whereas in aikido you might not try to block the punch, but gracefully move slightly and redirect the punch as it comes towards you the the force the person uses is instead used against them.
In a similar way, matching someone’s voice in a difficult conversation and then gradually changing your own voice tonality, tempo and volume is a great way to quickly defuse a situation.
These are essential NLP skills.