How Vocal Cords Produce Speech: From Airflow to Articulation

1. Initiation of Sound

Brain signals lungs to fill with air. Exhalation sends air through trachea to larynx (voice box).

2. Vocal Cord Vibration

Two elastic vocal folds (cords) span the airway. Air pressure brings them together; airflow pushes them apart, creating the glottis. High-velocity air through the glottis causes rapid vibration → sound.

3. Sound Modification

• Pitch: Tension/thickness of cords (tighter = higher)
• Quality: Shape/size of vocal tract (mouth, tongue, sinuses)

4. Articulation

Tongue, lips, jaw shape the sound into consonants and vowels (e.g., "b" = lips block then release air).

Speech = coordinated lungs, larynx, vocal cords, articulators.