Cepstral Analysis of Voice in Young Adults

The fundamental frequency and harmonic organization of voice can be quantified using cepstral measure. The two commonly studied cepstral measures are Cepstral Peak Prominence (CPP) and smoothened Cepstral peak prominence (sCPP). CPP is determined by measuring the amplitude difference from the highest peak of the cepstrum to the corresponding regression line, drawn directly below the cepstral peaks and when a smoothening factor is applied, sCPP is obtained. Cepstral analysis has been reported to be a reliable and valid measure for voice evaluation even for signals with high level of aperiodicity, which the time based measures fails to evaluate. Thus, the present study aimed to investigate the reference values for CPP and sCPP in young adults with normal voice in the age range of 20-40 years. Hundred adults in the age range of 20-40 years with equal number of males and females were considered and the task includes to phonate vowels /a/, /i/ and /u/ for five seconds each and to read "300 word Kannada reading passage" (Savithri & Jayaram, 2005) and the Bengaluru passage. The cepstral analysis was done using speech tool software (version 1.65). The data was subjected to statistical analysis using SPSS (version 21). The present study provides the reference values for CPP and sCPP across various stimuli.