Cepstral Analysis of Hypernasality after Surgery in Children with Cleft Palate

Objective: Evidence in hypernasality measurement using traditional acoustic tools remain unreliable because of technological limitations. To overcome these disadvantages, cepstral analysis was introduced. Hence, the present study investigated to observe any change in cepstral measures before and after cleft palate (CP) surgery. Materials and Methods: Fifteen normal subjects and fifteen CP subjects within 5-8 years of age participated. Each subject sustained vowel (/a/, /i/, and /u/) phonation for a minimum of 5 seconds, which was directly fed into Speech Tool software. Recordings of CP subjects were done two days before surgery and one month after surgery. Using Hillenbrand algorithm, cepstral peak prominence (CPP) and smoothed cepstral peak prominence (CPPS) parameters were extracted for further analysis. Descriptive statistics revealed higher CPP and CPPS values after surgery compared to before surgery. However, the cepstral values were less than normal subjects after surgery. Results: Results of MANOVA were statistically significant at p<0.005 for CPP and CPPS between normal vs. before surgery and only for CPPS between normal and after surgery. Increased cepstral measures after surgery would be due to better velopharyngeal closure, which in turn increases intra-oral breath pressure, thereby leading to synchronized harmonic organization of voice. Conclution: To conclude, the present study evidences a difference in cepstral measure before and after cleft palate surgery.