Illustration of nasal airflow (top), oral airflow (middle), and audio speech signal (bottom) associated with production of the sentence, "Sissy sees the sun in the sky." The speaker was a child with repaired cleft palate and velopharyngeal dysfunction. Inappropriate nasal airflow consistently occurs during the utterance -- indicated by the dashed vertical lines. Nasal air volume expended was 249 mL while oral air volume was 231 mL. Total air volume expended during the utterance, therefore, was 480 mL; average volume per syllable was 60 mL. The total volume expended during the utterance represents approximately 21% of the speaker's vital capacity.