Here's a quick story to demonstrate the power of tone when on the phone with a customer.
I'm not really a huge football fan, but my husband is a diehard 49ers fan. One day a few years ago I was at an industry conference in Las Vegas when my husband called me. Immediately after picking up the phone I could already tell that the 49ers won the game he was at. I could sense the excitement, and as such, also quickly became very excited.
Have you ever called someone and based on their tone could tell if they had a good or a bad day? Now put this into the perspective of what you do at the dealership on the phone. You might be saying the right words but not getting anywhere on account of having the wrong tone to your voice.
It's important to pay attention to your tone in addition to words, gestures, and posture so that you are presenting yourself accurately to your customers over the phone.