Children with loud voices are often placed at a disadvantage in society. Added to the modulation of the voice in childhood training is the narrowing of accepted emotional expression during socialization. Display of affect is confined within narrow boundaries in most cultures, and only allowed full, untrammeled public expression on limited occasions. Vocal training at a later age for those who choose it lasts a long time. Eight to ten years is normal for most singers with professional aspirations in most classical traditions, including Western classical music.
Instruction is athletic in nature, for it involves the training of muscles throughout the body.
The primary muscles are those of the mouth, throat, and breathing apparatus, but in effect every part of the body must be involved in the singing process. Singers must also learn to overcome inhibitions that would prevent them from producing full and expressive sounds in public. Since the singer is exposed and defenseless before the public, there may be involuntary reflexes such as adrenaline production that need to be brought under control through the training process lest they hinder the free and relaxed working of the voice. Meditative techniques that involve mental focus and bodily flexibility such as ta'i chi and yoga are used by many to aid in overcoming these difficulties. Singers in virtually every music tradition must learn to produce a culturally meaningful acoustic envelope for their vocalizations.