Consistency of laryngeal airway resistance in adult women.

Fifteen young adult women performed a noninvasive clinical technique for measurement of laryngeal airway resistance (Rlaw) during syllable (consonant plus vowel) production. The data were recorded from oscillographic records of translaryngeal air pressure (Ptr - Pph) and translaryngeal airflow (Vt1) over 2 days, during two time periods on each day. The overall mean Rlaw for the experimental sessions was 38.3 cmH2O/LPS (SD = 9.24). No significant differences were found within or between days or time of day for the subjects. The obtained values were similar to mean values obtained for men in a previous study (Smitheran and Hixon, 1981). Single subject phonation data were also gathered during a controlled intensity condition. The Rlaw range and standard deviation figures decreased significantly from the uncontrolled condition during syllable productions to the midrange intensity (75 dB SPL). This finding suggests that control of intensity is an important variable to consider during clinical sampling. The measurement procedure shows promise clinically as an index of actual laryngeal resistance under selected control conditions and in relation to simultaneous comparison of patient strategies used to regulate translaryngeal pressure and airflow.