Editing Vocal cord nodule (section)

=== Aerodynamic signs ===
If the nodules affect the closure of the vocal folds, airflow levels during speech may be increased in comparison to the speaker's habitual levels. However, airflow levels may still fall within the upper limits of the normal range.<ref name="Verdolini et al 2014 Vocal Fold Nodules" /> The degree to which an individual's airflow levels increase seems to depend on the severity of the injury. Subglottal pressure, the air pressure that is available below the glottis and in the trachea to produce speech, may be increased as well.<ref name="Colton et al 2006 Nodules" />