Title : A Cepstral Analysis of Pathological Voice Quality in the Korean Population using Praat

Authors : Geun-Hyo Kim, *Dong-Won Lim, Jae-Won Kim, Hee-June Park, and Yeon-Woo Lee

Abstracts:

SUMMARY: Objectives. This study aimed to investigate the reference values for cepstral peak prominence
(CPP) and smoothed CPP (CPPS) measured using Praat in Korean speakers with the normal, healthy and pathological voice.
Methods. A total of 4,524 Korean participants with vocally healthy (n = 410) and dysphonic voices (n = 4,114)
participated in this study. The speech task consisted of a sustained vowel /a/ and a sentence reading the Korean
passage "Walk". CPP and CPPS values were quickly and automatically measured in sustained vowel and continuous speech tasks using Praat script. Furthermore, three veteran speech language pathologists (SLPs) scored the
severity of dysphonia using the GRBAS scale (grade, roughness, breathiness, asthenia, strain) and Consensus
Auditory Perceptual Evaluation of Voice (CAPE-V).
Results. Three SLPs showed high inter- and intra-rater reliabilities (IRR) in auditory-perceptual (A-P) evaluation. Significant differences were confirmed in CPP and CPPS between the normally healthy and pathological
voice groups for both voice tasks (P < 0.01). The measured values of CPP and CPPS varied depending on the
laryngeal pathology. In the receiver operating characteristic (ROC) curve analysis, the CPP_Vowel (CPP_V),
CPPS_V, CPP_Sentence (CPP_S), and CPPS_S cut-off values were <21.5, <12.0, <19.7, and <10.1, respectively.
Through ROC curve analysis, it was confirmed that CPP and CPPS had excellent diagnostic accuracy in distinguishing disordered voice (area under the ROC: 0.951−0.966).
Conclusion. We investigated the reference values for CPP and CPPS measured with Praat for Korean speakers
and confirmed that cepstral analysis is a promising tool for differentiating pathological voice.
KEY WORDS: Cepstral peak prominence—Dysphonia—GRBAS—CAPE-V