Clinical Judgement of Hypernasality in Cleft Palate Children

Abstract

Speech clinicians, dentists, and physicians working in the area of cleft palate habilitation frequently judge whether or not a client's voice demonstrates excessive nasality. The judgment made may influence recommendations for surgical or prosthetic treatment of the palatopharyngeal mech— anism or for Speech lessons. Research has indicated that panels of pre—trained judges can rate nasality reliably under experimental conditions which include utilization of re— corded speech samples. In a study by Lintz and Sherman (6), 35 speech pathology students rated the voice quality of 10 nasal and 10 non—nasal speakers on a seven—point, equal appearing intervals scale. Judgments were madefrom tape recordings shortly after a special training session. A cor— relation of .89 was obtained for median scale values of 100 repeated judg— ments. Using the same scaling procedure, Spriestersbach (11) found that pre-trained groups of upperclassmen and graduate students in speech pathology and audiology can reliably rate nasality. Nasality was rated from taped samples, 30 seconds in length, of cleft palate speech when played both backward and forward. The correlations for median scale values of repeated nasality ratings was .96 for forward tape play and .90 for backward play. In a study designed to investigate the influence of speech context upon perceived nasality, Spriestersbach and Powers (12) asked 30 students in speech pathology to rate vowel and conversational speech samples of cleft palate subjects. Nasality was rated on a seven—point, equal appearing intervals scale. The correlation coefficient for two sets of median scale values for conversational speech ratings was .97; the correlation for two sets of median scale values for vowel production was .81. One study has indicated that single judges are also reliable in rating nasality under controlled conditions. Weiss (15) used the intraclass correlation procedure to determine if nasality could be scaled reliably by single Mr. Bradford,