Cepstral analysis in patients with a vocal fold motility impairment: advantages of the cepstrum over time-based acoustic analysis.

Abstract

To determine the usefulness of the smoothed cepstral peak prominence (CPPS) in sustained vowel as objective measure of dysphonia. This is a retrospective cohort study. 49 patients presenting a vocal cord motility impairment between 2012 and 2018 were included. Classical acoustic parameters, including jitter, shimmer and NHR, as well as the CPPS were obtained for each patient with a vocal cord motility impairment confirmed by means of a fiberoptic laryngoscopy. We calculated the S/E ratio of each patient to establish the glottal efficiency. An independent sample t test and a Pearson correlation test were used to compare data. Patients presenting a vocal cord motility impairment present abnormal values of the CPPS. Those patients presenting a vocal cord paralysis present lower values of those presenting a vocal cord paresis, with statistically significant difference (P < 0.005). CPPS and the S/E ratio present a moderate negative correlation (-0.29). Subjects with a vocal cord motility impairment present abnormal values for CPPS and those values are lower, the greater the motility impairment is. Therefore, CPPS presents as an objective, measurable and reproducible acoustic parameter of dysphonia that will improve the evaluation of patients presenting vocal pathologies.