Objective: Aerodynamic measures of voice have historically been acquired using sustained phonation tasks. This study seeks to determine whether there are differences in airflow during sustained phonation (MFs), in running speech (MFrs), or during phonation in running speech (MFvrs). We also seek to determine whether these patterns are diagnostically significant. Methods: Data were collected on 40 subjects (15 men, 25 women), ages 20–79, with a mean age of 53 in this prospective study. All participants received a comprehensive videostroboscopic evaluation and were deemed appropriate for voice evaluation and trial therapy. The Phonatory Aerodynamic System 6600 was used for data collection. The Comfortable Sustained Phonation and Running Speech protocols were used for data acquisition. Patient diagnoses were divided into five subgroups: benign lesions, vocal fold paralysis or paresis, muscle tension dysphonia, edema or laryngitis, and chronic cough. Statistical methods such as analysis of variance and Tukey tests assessed pairwise differences in the airflow rate. Pairwise Tukey multiple comparisons of means testing using a 95% family-wise confidence level were completed to determine the interrelationships of the pairs. Results: Differences were found among airflow measures (P value = 0.0152), pairwise comparisons of MFs-MFvrs pair (P value = 0.012), and diagnosis. No significance was found in MFs-MFrs (P = 0.051) or MFvrs-MFrs (P = 0.94) pairs. Mean flow rates were higher than the norms in MFs. The overall range of mean airflow was similar to those of published norms. Conclusion: Assumptions about mean airflow of connected speech should not be made based on sustained phonation tasks alone. No salient diagnostic characteristics were found by diagnosis.