The present study of vocal fold diadochokinesis in 18 young adult women yielded statistically significant differences in intensity (at percentiles 25%, 50%, 75% of range) of production for vowel /lambda/ repetition rate. In addition, there were statistically significant differences for vocal frequency and intensity effects for airflow rate through the vocal folds at the 25th, 50th, and 75th percentile points within the functional vocal range. Clinical applications of the data are suggested.