Obstruent Obstruent An obstruent is a speech sound such as , , or that is formed by "obstructing" airflow. Obstruents contrast with sonorants, which have no such obstruction and so resonate. All obstruents are consonants, but sonorants include both vowels and consonants. Obstruents are subdivided into plosives (oral stops), such as , with complete occlusion of the vocal tract, often followed by a release burst; fricatives, such as , with limited closure, not stopping airflow but making it turbulent; and affricates, which begin with complete occlusion but then release into a fricative-like release, such as . Obstruents are prototypically voiceless, but
Vocal cord dysfunction of the larynx (voice box). The glottic closure reflex (or laryngeal adductor reflex) serves to protect the airway, and it is possible that this reflex becomes hyperactive in some individuals, resulting in the paradoxical vocal fold closure seen in VCD. Two major causes of laryngeal inflammation and hyperresponsiveness are gastroesophageal reflux disease (GERD) and postnasal drip (associated with rhinosinusitis, allergic or nonallergic rhinitis, or a viral upper respiratory tract infection (URI)). Rhinosinusitis is very common among patients with VCD and for many patients, VCD symptoms are ameliorated when the rhinosinusitis is treated. GERD is also common among VCD patients, but