The voice starts to fully mature between the ages of 18 and 21, when the larynx reaches its adult size and position. However, the voice continues to develop and stabilize throughout the 20s, with changes in vocal fold structure and muscle coordination enhancing vocal stability, resonance, and stamina until the mid-20s or even later into the 30s. Thus, the voice "starts" its mature form in the early 20s but continues evolving beyond that.
If the question is about the TV show "The Voice," the 28th season is starting on Monday, September 22, 2025, at 8/7c on NBC.
