Voice box: The voice box, or larynx, is the portion of the respiratory (breathing) tract containing the vocal cords which produce sound. It is located between the pharynx and the trachea. The larynx, also called the voice box, is a 2-inch-long, tube-shaped organ in the neck.
We use the larynx when we breathe, talk, or swallow. Its outer wall of cartilage forms the area of the front of the neck referred to as the "Adams apple."
The vocal cords are two bands of muscle that form a "V" inside the larynx.
Each time we inhale (breathe in), air goes into our nose or mouth, then through the larynx, down the trachea, and into our lungs. When we exhale (breathe out), the air goes the other way. When we breathe, the vocal cords relax and air moves through the space between them without making a sound.
When we talk, the vocal cords tighten up and move closer together. Air from the lungs is forced between them and makes them vibrate, producing the sound of our voice. The tongue, lips, and teeth form this sound into words.
The esophagus, the tube that carries food from the mouth to the stomach, is just behind the trachea and the larynx. The openings of the esophagus and the larynx are very close together in the throat. When we swallow, a flap called the epiglottis moves down over the larynx to keep food out of the windpipe.