Acoustic analysis of the voice: Temporal, spectral and cepstral measurements in the normal voice with the Praat in a sample of Spanish speakers

Abstract

Acoustic analysis is a tool that provides objective information about the voice. In recent years, long-term average spectrum (LTAS) and cepstral measurements, such as the smoothed cepstral peak prominence (CPPs), have complemented the traditional measures, demonstrating in many studies a high correlation with the degree of severity of dysphonia. The objective of this descriptive study was to calculate the normal values of temporal, spectral and cepstral measures in a sample of 50 Spanish speakers (25 men and 25 women) in the Praat, taking into account the main factors that influence their reliability as the microphone type, the ambient noise level, the analysis program and the acoustic parameters used. Two voice samples were made for each subject: 1) sustained /a/ with which the CPPs were calculated and the parameters of the fundamental frequency (F0), noise and frequency and amplitude perturbations, and 2) a connected speech sample where CPPs and LTAS slopes were calculated. The results of the analysis with the sustained vowel show significant differences as a function of the sex in the F0, the jitter absolute and in all the parameters of the perturbation of the amplitude and the noise. In connected speech, significant differences were observed between men and women in the spectral slope obtained from the trend line through the LTAS and the CPPs.