What is a consequence of the vocal folds being in a position of closure or near closure?

When the vocal folds are in a position of closure or near closure, it leads to a specific consequence regarding their function during phonation. In this state, the vocal folds are primarily engaged in adduction, which means they come together or almost together, allowing for the control of airflow across the larynx.

The position of the vocal folds during phonation is crucial; with the vocal folds closed, the airflow from the lungs is momentarily obstructed. This builds up subglottal pressure beneath the folds. Once this pressure exceeds the resistance offered by the closed vocal folds, it forces them to vibrate, producing sound. Therefore, their closure is a necessary condition for phonation to occur effectively because it sets the stage for the cycles of opening and closing that happen during vocalization.

In this case, the process involves a mechanical interaction between the vocal folds and airflow, whereby they cannot open automatically without first being forced open by the subglottal pressure. It is important to understand the dynamics of this process, as the precise control over the tension and position of the vocal folds is what allows for varying pitches and qualities of voice. Hence, the position of closure directly relates to the generation of sound during phonation.