Vocal health assessment by means of Cepstral Peak Prominence Smoothed distribution in continuous speech

This work deals with an investigation on the Cepstral Peak Prominence Smoothed (CPPS) as a discriminator of vocal health in continuous speech. Individual CPPS distribution and its descriptive statistics in reading and free speech acquired with a headworn microphone were investigated. Two groups of subjects were involved: 72 dysphonic and 39 control volunteers according to videostroboscopy examinations. The 95th percentile showed the highest diagnostic precision in both the speech materials (Area Under Curve of 0.86), with lower values indicating a pathological status of voice. Similar best thresholds were found for both reading and free speech (18.1 dB and 17.9 dB, respectively), but the identical phonemic contents of the reading task allowed higher sensitivity and specificity to be obtained. The voice self-assessment was also evaluated in the healthy and pathological groups by means of a questionnaire, namely the Italian version of the Voice Activity And Participation Profile. Significantly different scores were obtained by the two groups in all the sections of the questionnaire, thus highlighting that vocal problems are actually perceived by dysphonic people. Moreover, the 95th percentile resulted in a strong correlation with the sections of self-perceived voice problem and daily communication.