The identification of nasal obstruction through clinical judgments of hyponasality and nasometric assessment of speech acoustics.

This study examined the records of a consecutive series of 79 patients referred for evaluation at the Oral-Facial and Communicative Disorders Program during a 3-month period in 1989. The purpose was to determine whether clinical judgments of hyponasality, based on a six-point equal-appearing interval scale or an acoustic assessment with a Kay Elemetrics nasometer could provide information concerning nasal airway patency comparable to that obtained by means of aerodynamic measurement techniques. Among the 40 adults in the series, the sensitivity of hyponasality ratings was 0.55 when nasal airway impairment was defined as a condition in which the airway was less than 0.40 and 0.71 when the definition was limited to airways of less than 0.30 cm2. Specificities for the two groups were 0.89 and 0.85, respectively. Similarly, the sensitivity of nasometer ratings was 0.30 for the first group and 0.38 for the second group, while the specificity for the two groups was 0.83 and 0.92, respectively. Comparable analyses for children were not possible because of the extent to which nasal airway size varies in children younger than 15 years of age. Possible reasons for the findings and their clinical significance are discussed.