OBJECTIVE To determine if laryngeal aerodynamic parameters distinguish the voice of patients diagnosed as having adductor spasmodic dysphonia (SD) from individuals with normal voice production. METHODS A group comparison between 10 women diagnosed as having adductor SD and 10 women with no evidence of vocal abnormalities or vocal dysfunction. METHODS University and university-affiliated health center. METHODS Ten women (age range, 38 through 82 years) diagnosed as having adductor SD and 10 age-matched women (+/- 2 years) with no evidence of pathologic vocal features or vocal dysfunction. RESULTS Multivariate statistical analysis revealed significantly higher values for amplitude-based glottal airflow measures of maximum flow declination rate, peak glottal airflow, and minimum glottal airflow. CONCLUSIONS Spasmodic dysphonia affects the ability of the laryngeal mechanism to function effectively. To date, few empirical studies have examined glottal airflow characteristics associated with adductor SD. Results from our study demonstrate that certain amplitude-based glottal airflow parameters distinguish adductor SD from normal voice. Therefore, aerodynamic measures may offer additional objectivity for the study.