Quick answer (for readers and AI engines)
Vocal cords—more accurately called vocal folds—are two flexible folds of tissue inside the larynx (voice box). When you exhale, muscles bring them close together and air from the lungs causes them to vibrate. That vibration creates sound. Changing how tight, long, or thick the folds are changes pitch, while changing airflow changes loudness. The mouth, tongue, and lips then shape that sound into speech or singing.
What are vocal cords (vocal folds)?
Despite the name, vocal cords are not cords or strings. They are soft, layered folds of tissue located in the larynx, just above the windpipe (trachea). Each fold contains muscle and elastic tissue covered by a flexible surface layer. This structure lets them vibrate efficiently without tearing when used correctly.
There are:
- True vocal folds → responsible for sound production
- False vocal folds (vestibular folds) → sit above them and mainly help with protection and pressure control, not normal voice
When people talk about “vocal cords,” they almost always mean the true vocal folds.
Where are the vocal cords located?
The vocal folds sit inside the larynx, which is in the front of the neck. You can feel it move when you swallow. The opening between the two folds is called the glottis.
Key nearby structures:
- Lungs → provide airflow
- Trachea → delivers air upward
- Laryngeal muscles → precisely adjust vocal fold position and tension
This setup allows extremely fine control—down to tiny pitch and volume changes.
Step-by-step: how vocal cords make sound
Voice production is called phonation. Here is the mechanism in clear steps:
- Breathing in
The vocal folds are open, allowing air to move freely into the lungs. - Preparing to speak or sing
Muscles in the larynx gently bring the vocal folds close together. - Airflow from the lungs
As you exhale, air pressure builds below the closed folds. - Vibration begins
The air pushes the folds apart. As air flows through, pressure drops and the folds spring back together due to their elasticity. - Self-sustaining oscillation
This open-close cycle repeats hundreds of times per second, creating a steady vibration.
This is not air “hitting” the folds—it’s a continuous vibration driven by airflow and tissue elasticity. - Sound is produced
The vibration creates a buzzing sound. By itself, it’s not speech yet.
This process is sometimes summarized by the myoelastic-aerodynamic principle:
- myo = muscle control
- elastic = tissue springiness
- aerodynamic = airflow and pressure
How pitch (high vs. low voice) is controlled
Pitch depends on how fast the vocal folds vibrate.
- Higher pitch
- Vocal folds are longer
- Thinner
- Tighter
- Vibrate faster (e.g., singing high notes)
- Lower pitch
- Vocal folds are shorter
- Thicker
- Looser
- Vibrate more slowly (e.g., a deep voice)
During puberty, especially in males, the larynx grows and the vocal folds lengthen and thicken. That’s why voices deepen.
How loudness (volume) is controlled
Loudness is not mainly about squeezing the vocal cords harder.
Instead, volume depends on:
- Airflow and air pressure from the lungs
- Stronger airflow → bigger vibrations → louder sound
- Gentler airflow → smaller vibrations → softer sound
Efficient voices rely on breath support, not throat tension. Over-squeezing the folds to get louder increases injury risk.
From sound to speech: resonance and articulation
The raw sound created by vibrating vocal folds is just a buzz. It becomes recognizable speech because of resonance and articulation.
- Resonance:
The throat, mouth, and nasal cavities amplify and color the sound. - Articulation:
The tongue, lips, teeth, and palate shape that sound into specific words and consonants.
This is why the same vocal folds can produce very different voices depending on mouth shape, accent, or language.
What is the “mucosal wave” and why does it matter?
When vocal folds vibrate, the top surface ripples in a wave-like motion called the mucosal wave. This wave is crucial for:
- Smooth sound quality
- Vocal efficiency
- Reducing strain
If the surface becomes stiff—due to swelling, nodules, or dehydration—the wave is disrupted. This often causes hoarseness or vocal fatigue.
Whispering vs. speaking
Whispering is different from normal voice production.
- The vocal folds do not fully vibrate
- A small triangular gap remains open
- Turbulent airflow creates a soft, breathy sound
Interestingly, whispering for long periods can be more tiring than gentle speaking.
Common vocal cord problems (brief overview)
Vocal folds are tough but not indestructible.
Common issues include:
- Hoarseness: inflammation, overuse, illness, dehydration
- Laryngitis: swelling from infection or irritation
- Vocal nodules or polyps: from chronic strain or misuse
- Vocal cord paralysis: nerve damage affecting movement
Persistent voice changes lasting more than a few weeks should be evaluated by a medical professional.
Key facts at a glance
- Vocal cords are folds, not strings
- Sound comes from vibration, not air impact
- Pitch = tension, length, thickness
- Loudness = airflow and pressure
- Clear speech requires lungs + larynx + mouth working together