Normal
1 Column of air pressure moves upward towards vocal folds in "closed" position 2, 3 Column of air pressure opens bottom of vibrating layers of vocal folds; body of vocal folds stays in place 4, 5 Column of air pressure continues to move upward, now towards the top of vocal folds, and opens the top	(click for larger image)	6-10 The low pressure created behind the fast-moving air column produces a Bernoulli effect which causes the bottom to close, followed by the top 10 Closure of the vocal folds cuts off the air column and releases a pulse of air. New vibratory cycle – repeat 1-10.
Abnormal Vocal Fold Scarring – Impact on Opening and Closing During Vibratory Cycle
2 Stiffness from Scar increases amount of air pressure needed to open vocal folds hoarseness, increased voice effort, voice fatigue	(click for larger image)	8 Stiffness from Scar decreases Bernoulli effect's efficiency to close vocal fold hoarseness, breathy voice

Although quite simplified, this is a schematic representation of what could go wrong when one has scarred vocal folds.

1. Scarring affects the vibration of the vocal folds making it harder to open (panel 2) and harder to close (panel 8) compared to normal vocal folds (see normal vocal fold parallel diagram).  Hence, patients with scarring in one or both vocal folds usually complain of increased effort and therefore voice fatigue. Depending on severity of scarring, the voice may be hoarse all the time, or just when added inflammation occurs as when one has a cold or reflux laryngitis. Also, when a cold goes away, the hoarseness that was precipitated by the cold does not go away when the cold lifts because the scarred area would be expected to heal slower if not worsen with each inflammatory insult.

2. Panel 2 also depicts the increased air pressure needed to open a scarred vocal fold and the asymmetry in vibration (cycles of opening-closing) when one fold is stiffer (the scarred vocal fold) than the normal vocal fold. This would be reflected in a change of voice quality that would be more noticeable on singing. Worse scar leads to worse voice changes.

3. Scarring at the inferior (bottom) edge of the closing (striking) surface of the vocal folds is harder to detect. Usually the superior (top) edge of the closing surface can and will compensate.

This diagram can be found in Vocal Fold Scarring: Diagnosis.