How to change your voice?

You can change your voice by doing vocal exercises to strengthen the vocal muscles and vocal chords. My cousin had a croaky and harsh voice and she changed it to a deep and crisp one. To reach her proper conversational pitch she recorded her voice and practiced in private. She used to sing or talk loudly after relaxing all muscles. She used to do this by placing her hand over her chest so that she could feel the vibration of her sound. She was so conscious even in casual conversations that she would convert it in to a drill to practice normal pitch. She also took proper care of her vocal chords by constantly hydrating and moistening it. She preferred lukewarm or warm fluids than cold drinks. Even now, she does vocal exercises to tone up the voice box and to gain a smoother and deeper pitch.