Vocal Folds

Anatomical

Quick Definition

The two bands of muscle and tissue in the larynx that vibrate to produce the sound of the voice.

Factual Definition

Paired structures within the larynx composed of the vocalis muscle (the medial portion of the thyroarytenoid muscle) covered by mucosa. They vibrate through a cycle of opening and closing caused by subglottic air pressure and the Bernoulli effect, producing the sound source that is then shaped by the resonating cavities above.

Full Explanation

The vocal folds (also called vocal cords, though ‘folds’ is more anatomically accurate) are the primary sound source of the human voice. They sit within the larynx, stretching from the thyroid cartilage at the front to the arytenoid cartilages at the back.

During phonation, air pressure from below pushes the folds apart, after which they snap back together due to their elasticity and the Bernoulli effect. This rapid vibration (from around 100 Hz in low male voices to over 1000 Hz in high soprano notes) creates the ‘buzz’ that is then filtered by the vocal tract to produce recognizable voice and vowels.

The thickness, length, and tension of the vocal folds can be adjusted by various laryngeal muscles, allowing for the range of pitches and voice qualities a singer can produce.

How Different Methods Define This

This term may be used differently across vocal pedagogy traditions:

Voice Science
Multilayered vibrating structures consisting of the thyroarytenoid muscle, vocal ligament, and covering mucosa. Their vibratory pattern is described by the body-cover theory of phonation.
Source: Voice science and laryngology
Estill Voice Training
Addressed through the 'True Vocal Fold' figures: onset/offset (how they come together), Body-Cover (thick/thin/stiff), and glottal shape.
Source: Estill Voice Training