CBSE Class 10 Answered

The sound of each individual voice is determined by the size and shape of the vocal cords and the size and shape of the throat, nose, and mouth (the resonating cavities). All these differ in different individuals. Humans have vocal folds which can loosen, tighten, or change their thickness, and over which breath can be transferred at varying pressures. The shape of chest and neck, the position of the tongue, and the tightness of otherwise unrelated muscles can be altered. Any one of these actions results in a change in pitch, volume, timbre, or tone of the sound produced. Sound also resonates within different parts of the body, and an individual's size and bone structure can affect the sound produced by an individual.

Men and women have different vocal folds sizes. The difference in vocal folds size between men and women means that they have differently pitched voices. Additionally, genetics also causes variances amongst the same sex.