Central nervous system control of interactions between vocalization and respiration in mammals.

The purpose of this review is to examine what is known regarding the competition and synergy between respiratory and airway protective systems with vocalization for speech. It was demonstrated that there are integrative neural mechanisms between vocalization for speech and upper airway protective mechanisms at both the brainstem levels and within cerebral networks. When there is competition between cortical control of learned volitional tasks, usually the upper airway protective systems predominate (eg, the laryngeal adductor response overrides laryngeal muscle control for voice and respiratory tasks). On the other hand, volitional swallowing overrides the laryngeal adductor response. Possible mechanisms for enhanced control of upper airway systems and rehabilitation of abnormal other upper airway systems was also examined. Recently, intensive clinical training using volitional breathing and swallowing tasks has been shown to modulate hyper-reactive sensory driven reflexes such as cough and paradoxical vocal fold movement disorder secondary to laryngeal hypersensitivity.