Hello! I test again , when I went to hairstyle to cut the hair my voice changed again and I need to edit it one more time on character editor screen access by pressing V on world map screen. I think it is a real bug.
Hello there. I thought That I had the same problem as described on this post, but when my character reached 21 years old, I opened the character edition screen (press V on Map View) and I realized that all four voices were there and also my face and chest hair grew up. (Sorry about my English, I am improving it)