Can a person really change their voice?

Voices are created in the first place. We all learned to speak through imitation because humans are not born with the ability to communicate verbally. The evolution in the human body that led to speech took 100,000 years to happen and it still takes 2 years for a baby to learn to use their voice to form language. You created the voice you have, and, with time and the right training, you can create something different if you want to.