Several parameters are used for the assessment of phonatory function and voice quality in clinical settings. Glottic airflow, subglottal pressure, mean phonation time, laryngeal resistance and voice efficiency are the most commonly used aerodynamic parameters. Aerodynamic analysis is developed to evaluate phonatory energy source and to estimate laryngeal efficiency. Also these measurements have shown the good correlation with perceptions of breathiness and findings of glottic competence. Aerodynamic study is important to understand relationships between pulmonary and phonatory function.