The larynx and vocal cords can vibrate more or less depending on the constitution of each person, but also on their age. On the other hand, the so-called "vocal footprint" is determined by the shape of the upper laryngeal tract, which varies from one individual to another, so the resonance of the voice also varies. The first cry of a baby , according to experts, has a medium tonality between 440 and 500 Hz (very high). By age seven , the frequency of the voice has dropped by 200 Hz, around 295 Hz for girls and 268 Hz for boys. In reaching puberty, testosterone causes male voice increases muscle mass, the walls of the larynx to thicken, grow the laryngeal cartilages, vocal cords and the voice of men lengthen it becomes more serious. The pitch of voice in boys decreases by approximately one octave. The voice of female adolescents also changes due to the action of estrogens on the vocal cords. Furthermore, frequent "roosters" are produced by adaptation to the new modulation.
In old age , testosterone decreases in men and the voice becomes acute again. In women, on the contrary, it becomes slightly more severe from estrogens. In addition, the vocal cords lose elasticity and collagen fibers .
