Correlation of Perceived Nasality with the Acoustic Measures (One Third Octave Spectral Analysis & Voice Low Tone to High Tone Ratio)

Abstract

Aim: The perceived hypernasality in speech can be evaluated using various qualitative and quantitative methods. The present study aimed to investigate, compare and correlate acoustic parameters one third octave spectra analysis and Voice Low Tone to High Tone Ratio (VLHR) with perceived nasality in children with repaired cleft lip and palate (RCLP) and in age and gender matched typically developing children (TDC). Methods: The study included 73 children (47 RCLP & 26 TDC) in the age range of four to twelve years. The spontaneous speech and sentences were recorded and analyzed for nasality using standardized perceptual four point rating scale. Based on the severity of perceived nasality children were divided into three groups namely normal, mild, and moderate to severe. The production of the vowel /a/ by participants was subjected to acoustic analysis using VLHR and One third octave spectra analysis using MATLAB software. Results: The results indicated significant differences in spectral amplitude measured using one third octave spectra analysis at high frequency region for the vowel /a/ between TDC & RCLP. The VLHR measures were not indicating statistically significant difference and relation with the perceived nasality. Conclusion: One third octave spectra analysis is an effective measure in differentiating the nasality and found to have a significant correlation with perceived nasality in children with RCLP. Hence, one third octave spectra analysis can augment the perceptual evaluation to provide additional information to arrive at a diagnosis.