Perceptive and apparative evaluation of voice quality in cleft palate patients.

Background: In Anglo-American literature, prevalences as high as 41% are re ported for voice disorders in cleft tip and palate (CLP) patients. Because of considerable variability in the reported findings and because no prevale nce data are available for the German-speaking area, a screening study was conducted. Method: 154 patients with CLP were examined. Voice quality was a ssessed perceptively according to the rbh-system (roughness, breathiness, h oarseness). Suprasegmentals and nasal resonance were also assessed. Using a new computer programme for the apparative analysis of voice quality, data for pitch, intensity and pertubation (jitter and shimmer) were obtained for 4 sustained vowels. Results: Based on perceptual analysis, we found that t he prevalence of severe Voice disorders in CLP patients was 6.5% which is l ower than reported in most other studies. The incidence of voice disorders in CLP patients is numerically only slightly higher than in the normal popu lation. The acoustic measurements confirm the results of perceptual analysi s. Since the prevalence of severe voice disorders was low, none of the pert ubation quotients differentiated between modal and disordered voices. A wea k correlation was found between jitter and the ratings for hoarseness. Conc lusions: 1. While it is appropriate to assume a higher potential risk for v ocal dysfunction in CLP patients the actual prevalence in the patients exam ined is numerically only slightly higher than in normals. 2. For patients w ith Voice disorders, apparative diagnostics of voice quality is a useful an d practical adjunct to perceptual analysis which helps profiling individual patients and helps the professional to make decisions for therapy.