Why is your voice changing?
The voice changes because the larynx, also called the voicebox, grows larger during puberty. The vocal cords also get thicker and longer, which makes them vibrate at a lower frequency, producing a deeper sound.
In addition, the muscles around the larynx develop, which helps to increase the range of vocal pitches and control the tone of the voice. Finally, the sinuses in the head and neck also enlarge, which affects the resonance of the voice, giving it a fuller and more mature sound.