The vocal folds are the main structure of human vocalization and are located in the laryngeal cavity, one on each side. The vocal folds open during breathing and close during pronunciation. It is well known that vocal folds vibrate to produce sound, but it is not entirely produced by the vocal folds themselves. The two vocal folds close together during articulation and are vibrated by the airflow exhaled from the lungs. The fundamental sound from the vocal folds is very small, and this fundamental sound is enhanced and changed by the resonance of the lungs, trachea, nose, sinuses, pharynx and mouth to become the heard sound. The vocal cords vibrate at high speed and collide with each other during vocalization. For people who use their voice a lot, the vocal cords are in a vibrating position thousands of times a day, and they collide with each other more than a million times. Compare this “micro-collision” of the vocal cords with the clapping of hands during a concert or pre-game rally. If you clap your hands an average of one time per second, that’s 600 hand claps in five minutes, and you’re sure to have felt the pain in your hands. However, even though the vocal cords collide with each other at about the same rate as the hand clap, the difference in endurance between a million claps and six hundred claps is more than a thousand times greater. How does the vocal cord tissue withstand such heavy wear and tear? Let’s look at the structure of the vocal cords. The vocal cords are like a large mattress, and their structure changes as we age. The vocal cords of an infant are like a large water bag filled with water, but as they age, the muscle and connective tissue fibers of the vocal cords gradually increase in composition, so that it is like a “large water bag” with coils of spring and cotton thread. It has a tougher lining with long collagen molecules similar to cotton threads, short curly molecules of elastin similar to coil springs, and hyaluronic acid similar to lubricant, making this large water bag like a waterbed cushion. Thanks to the elastic and shock-absorbing components, the vocal cords withstand collisions just as well as the waterbed withstands people bouncing on it. Although our vocal cords have good endurance, they are not without limits. If you use your voice too often, such as singing in high notes or talking for long periods of time without resting, inflammation and edema can easily occur. If the structure of the vocal cords becomes abnormal, the voice will become hoarse. Many diseases can affect the voice, such as acute and chronic inflammation of the vocal cords, vocal cord nodules, and vocal cord polyps. Prolonged use of the voice, instant shouting, long-term smoking, heavy drinking, and work fatigue can easily cause abnormalities in the structure of the vocal folds. The maintenance in daily life is important for the protection of the vocal folds.