Human voice

Lore & Background

The human voice is generated by a mechanism subdivided into three parts: the lungs, the vocal folds within the larynx, and the articulators. The lungs act as a pump to produce airflow and air pressure to vibrate the vocal folds. The vocal folds then vibrate to create audible pulses that form the laryngeal sound source. The muscles of the larynx adjust the length and tension of the vocal folds to fine-tune pitch and tone. The articulators—tongue, palate, cheek, lips—articulate and filter the sound from the larynx. Adult men and women typically have different sizes of vocal folds, reflecting differences in larynx size. Male vocal folds are between 17 mm and 25 mm in length, while female vocal folds are between 12.5 mm and 17.5 mm. The folds are attached to the arytenoids cartilages at the back and the thyroid cartilage at the front. They have a three-layer construction of epithelium, vocal ligament, and muscle. Above each vocal cord is the vestibular fold, or false vocal cord. Human spoken language makes use of dynamic modulation of voice pitch and the degree of separation of the vocal folds (adduction or abduction). The ability to vary this quickly has a strong genetic component, as vocal fold adduction helps keep food from passing into the lungs. Children can learn to use this action consistently during speech before age two by listening to adults. Voiceless speech sounds involve an abductory gesture, while an adductory gesture may produce a glottal stop.

Reader's Guide

The human voice is a fundamental tool for communication and artistic expression, enabling spoken language, singing, and emotional modulation. Its significance lies in its role as the primary means of conveying information and emotion across all human societies. The voice's unique characteristics—pitch, timbre, and volume—are shaped by the size and shape of the vocal folds, vocal tract, and body, making each voice distinct. The ability to modulate the voice allows for the expression of emotions such as anger, surprise, fear, happiness, or sadness, and can reveal the age and sex of the speaker. In music, singers use the voice as an instrument, with voice types categorized by range, such as bass, tenor, soprano, and contralto. The study of vocal registers—different vibratory patterns of the vocal folds—helps explain how singers produce varied sounds and project their voices over accompaniment. The voice's legacy is enduring, as it remains central to human interaction, from everyday conversation to performance arts, and continues to be a subject of scientific study in physiology, phonetics, and acoustics.

Did You Know?

• The human voice includes talking, singing, laughing, crying, screaming, shouting, humming, and yelling.
• Adult male vocal folds are between 17 mm and 25 mm in length; female vocal folds are between 12.5 mm and 17.5 mm.
• The vocal folds have a three-layer construction: epithelium, vocal ligament, and muscle.
• Children can learn to use vocal fold adduction consistently during speech before the age of two.