My T and I once joked about how she had a "therapy voice" and a normal voice. It wasn't strange or awkward or anything but when things would get serious or intense her voice/tone would change to the "therapy voice". I guess just a softer, slower sound. But it was great bc it was very calm and gentle. Then for casual conversation and such it was her "normal voice" but it was still really calm and non threatening. I spoke to her on the phone before meeting her and was actually really surprised at what she looked like...for some reason based on her voice I was expecting someone different I guess...
I think a therapists tone can be really important and convey a lot of meaning sometimes.