Prevalence of Perceived Acoustic Deviations Related to Laryngeal Function Among Subjects with Palatal Anomalies

Abstract

It is commonly accepted that speakers With inadequate velo—pharyngeal closure often employ compensatory adjustments of the speech mechanism in attempting to establish acceptable speech. One such compensatory movement is the glottal-stop (2, 21, 22, 23) which entails improper usage of the vocal cords. Spriestersbach, ct. al., (22) report the frequency of glottal-stops to be inversely related to the adequacy of velo—pharyngeal function or intraoral pressure. If the laryngeal area is a focal point for compensatory action, it is conceivable that other acoustic deviations may occur because of hyper— or hypo-function of laryngeal musculature (2, 5, 6', 7, 15). In making a proper descriptive diagnosis of speakers with velo-pharyn-geal inadequacy, characteristics other than hypernasality must be noted. Some of these characteristics are related to hyper-and/or hypo—function of the laryngeal musculature and are often described by such terms as hoarseness, huskiness, breathiness, throatiness, vocal fry, and/0r stri— dency. Many authors have noted such voice qualities among speakers With vale—pharyngeal anomalies (2, 5, 6, '7, 10, 12, 13, 14, 15, 23, 24, 25, 26'). Table 1 summarizes several studies documenting the prevalence of voice disorders other than hypernasality among both non-cleft and cleft palate subjects. The failure of these investigators to arrive at similar prevalence figures may be attributed to several factors: Differences in age of sample, failure to develop explicit definitions as to the nature of the voice disorders , and lack of standardized rating systems that could be readily dupli— cated by others. The prevalence and description of voice disorders other than hyperna-sality has been reported; some authors feel theSe voice disorders mask or Mrs. Marks is Research Speech Pathologist,