The human voice produces sounds in the following manner:

1. Air pressure from the lungs creates a steady flow of air through the trachea (windpipe), larynx (voice box) and pharynx (back of the throat).
    
2. The vocal folds in the larynx vibrate, creating fluctuations in air pressure that are known as sound waves.
    
3. Resonances in the vocal tract modify these waves according to the position and shape of the lips, jaw, tongue, soft palate, and other speech organs, creating formant regions and thus different qualities of sonorant (voiced) sound.
    
4. Mouth and nose openings radiate the sound waves into the environment.