Influence of the high and low intraoral pressure consonants on the speech nasality and nasalance

Abstract

Hypernasality is the most characteristic speech symptom in cleft palate. Among the objective methods for its diagnosis, nasometry has been the most efficient one with good correlation to the perceptual assessment. Objective: To verify speech nasality and nasalance between high and low intraoral pressure stimulus in cleft lip and palate subjects previously repaired. Material and Method: This prospective study will be developed in the Laboratory of Physiology - HRAC-USP (approved by the Ethical Committee in Human Being Research of the hospital). A minimum of 44 cleft palate±lip subjects, both genders and with age e6 years will be evaluated. The patients will be submitted to nasometry (6200-3 IBM model, Kay Elemetrics Corp) and to the simultaneous speech recording by using a sound system (software WaveStudio-Sound Blaster Creative), and a unidirectional microphone (Sony, ECM-MS957 model), connected to a notebook. The speech samples will be composed of two sets of five sentences each: one predominantly comprising high intraoral pressure samples and the other exclusively comprising low intraoral pressure consonants. To calculate the nasalance, the numerical ratio between the nasal acoustic energy and the total (nasal and oral) acoustic energy will be used multiplied by 100 (%). The samples will be recorded in a portable memory device for the analysis of the hypernasality by three experienced examiners in the evaluation of cleft palate speech to classify the symptom using a 4-point scale: 1 = absent; 2 = mild; 3 = moderate; 4 = severe. The values of nasalance obtained for both speech stimuli will be compared by paired "t" test and Wilcoxon test to verify the nasality (p<0.05). For inter-examiner agreement in the hypernasality assessment Kappa coefficient will be used, in which a coefficient below zero indicates no agreement; from 0-0.20 indicates slight agreement; 0.21-0.40 fair agreement; 0.41-060 moderate; 0.61-0.80 substantial and 0.81-1.0 almost perfect agreement. Additionally, Spearman's correlation test will be applied between quantitative (nasalance scores) and qualitative data (degree of hypernasality). Therefore, it is expected that the outcomes of the present study will help the clinician to select the speech stimulus that best identify the hypernasality.