Normal Voice Production

When you want to speak your brain sends a signal to the muscles of respiration , the laryngeal muscles, and your muscles of articulation telling them to prepare to make sound. You then must inhale. When you inhale, your vocal folds are open, your diaphragm muscle contracts, which causes a vacuum in the lungs and air rushes in. Just before you make sound, the vocal folds adduct (come together) and close off the top of the airway. When you build enough air pressure below the vocal folds (subglottic pressure), then a puff of sound emerges.

As long as the breath pressure is sufficient to overcome the subglottic pressure, then voicing continues. Once sound is generated by the vocal folds, then it is the job of the pharynx, mouth, tongue, jaw, soft palate, etc. , to shape that sound into different vowels and consonants.

We rarely think about the intricate balance and manipulation of these voicing components, unless there is a problem.