The Adam's apple is a cartilage that protrudes from the front of the neck and is more prominent in men than in women. It is formed by the fusion of the thyroid cartilage, which houses the vocal cords, and it does not play a direct role in voice production.
The vocal range is determined by the frequency at which the vocal cords vibrate. Longer and thicker vocal cords tend to produce lower pitches, while shorter and thinner vocal cords produce higher pitches. The shape and size of the vocal tract, including the sinuses, mouth, and throat, also affect the resonance and timbre of the voice, influencing the overall vocal range.
Factors such as vocal training, vocal health, and individual vocal anatomy contribute more significantly to the range of a singing voice than the size of the Adam's apple. A well-trained singer can develop vocal techniques to expand their vocal range regardless of the size of their Adam's apple.