Vocal cord adduction while sniffing.

The movement of vocal cords while sniffing was observed by fiberscope and electromyogram. Nasal airflow rate was compared while sniffing and during normal respiration. Fiberscopic and electromyographic observations revealed that the vocal cords adduct while the subject is sniffing. The olfactory sense was not needed. It also was different from the defensive laryngeal reflex closure. The nasal airflow rate during sniffing was less during inspiration than during normal respiration. Inhalation while sniffing was different from that of respiration. It is concluded that the vocal cords adduct while sniffing, and that the nasal airflow rate might be less during sniffing than during normal respiration.