Acoustic measurements of CPPS and AVQI pre and post speech therapy

PURPOSE: To compare the acoustic measurements of Cepstral Peak Prominence-Smoothed (CPPS) and Acoustic Voice Quality Index (AVQI) at pre- and post-voice therapy times. METHODS: This is a before and after intervention study, with retrospective data collection. Twenty-two subjects with a mean age of 49.9 years participated in the study. The vocal therapy occurred between the years 2016 to 2019 in a teaching clinic, and the subjects had vocal samples collected before and after the therapeutic processes. CPPS and AVQI data extractions were performed during pre- and post-therapy. In order to characterize the sample, auditory-perceptual evaluation (APE) regarding the overall degree of vocal deviation at pre- and post-therapy moments was performed. The data were analyzed statistically. RESULTS: The APE data indicated a decrease in the median values of overall vocal deviation degree at the post-therapy stage for both the vowel (p=0.00) and number (p=0.00) samples. The average CPPS for the vowel was 14.53 pre-therapy and 16.37 post-therapy (p=0.01); for the number emission, it was 8.22 pre-therapy and 9.06 post-therapy (p=0.02), there was a difference in the CPPS of the vowel and numbers indicating vocal improvement at post-therapy. The average AVQI was 2.27 pre-therapy and 1.54 post-therapy (p=0.05). There was an improvement in the AVQI results, with borderline p-value. CONCLUSION: Vocal therapy produced changes in the general degree of vocal deviation, as well as in CPPS and AVQI measurements, and the results at the post-therapy moment are similar to those of vocally healthy individuals.