Vocal cords, or vocal folds as they are often more accurately called, are small but powerful structures within the human body. These bands of smooth muscle tissue are located in the voice box, known as the larynx, and are fundamental to the production of sound.
The Basic Visuals: What You See
Healthy vocal cords appear pearly white or off-white. They are not string-like as the term “cords” might suggest, but rather appear as two small folds or bands of tissue. In a relaxed, open state, they form a V-shape or an inverted Y-shape, allowing air to pass through.
These folds possess a smooth, glistening, and moist texture due to a protective mucous membrane that covers them. The size of vocal cords varies between individuals, with adult male vocal cords measuring between 1.75 to 2.5 centimeters in length. Adult female vocal cords are shorter, ranging from 1.25 to 1.75 centimeters. This difference in length and thickness contributes to the variations in vocal pitch between sexes.
Beyond the Surface: Structure and Location
The vocal cords are located within the larynx, in the neck. This voice box sits above the trachea, or windpipe, and below the pharynx, the part of the throat behind the mouth and nasal cavity. They are attached anteriorly to the thyroid cartilage, often recognized as the “Adam’s apple,” and posteriorly to the arytenoid cartilages.
Vocal cords are not simple cords but complex folds of mucous membrane stretched across the larynx. Each vocal fold is composed of multiple layers: an outer layer of epithelium, a middle layer called the lamina propria, and an innermost muscular layer known as the vocalis muscle. The lamina propria has three sub-layers, with the superficial layer being gel-like, allowing for vibration, and the deeper layers forming the vocal ligament for structural support. This layered structure contributes to their characteristic color and flexible texture.
Appearance in Action: How They Move and Change
The visual appearance of vocal cords is dynamic, changing depending on activity. During quiet breathing, the vocal cords are open, forming a V-shape to allow air to pass into and out of the lungs. This open position ensures an unobstructed airway.
When speaking or singing, the vocal cords come together, a process called adduction. Air from the lungs then pushes through the narrow space between them, causing them to vibrate rapidly. This vibration creates sound, and during this action, the vocal cords appear to blur or oscillate at hundreds of times per second. Changes in vocal cord tension and length, controlled by laryngeal muscles, alter their appearance and impact the pitch of the sound produced. For instance, higher pitches involve longer and thinner vocal folds.
During swallowing, the vocal cords close tightly to protect the airway. This closure prevents food and liquids from entering the trachea and lungs, a protective reflex. The larynx also elevates and moves forward during this action, further contributing to airway protection.