The Relationship between Traditional Acoustic Measures and Cepstral Analysis of Voice.

Introduction: In this study, the correlations between traditional acoustic measures (TAMs) and cepstral analysis (CA) were explored in Persian.

Methods: This investigation was a cross-sectional study including 179 dysphonic (n = 141) and normophonic (n = 38) speakers. The TAMs (jitter, shimmer, and noise-to-harmonic ratio) and CA (cepstral peak prominence and cepstral peak prominence smoothed) values were obtained during vowel prolongation, reading a standard sentence, and a nonstandard running speech sample using Praat software. The difference of acoustic measures between normophonic and dysphonic speakers and intercorrelation among acoustic measures and correlation between the acoustic measures and perceived dysphonia levels were analyzed with independent t test, Mann-Whitney U test, Pearson, Spearman, and Kendall's Tau-b correlation tests using IBM SPSS Statistics.

Results: The findings showed that dysphonic speakers had higher TAM values and lower CA values than normophonic speakers (p < 0.05). In dysphonic speakers, a large correlation was discovered among all acoustic measurements (r = 0.52-0.96; p < 0.05), while in various perceived dysphonic speakers, there was a correlation of varying strength (r = 0.25-0.97; p < 0.05). Ultimately, there was a significant small-to-large correlation between the acoustic measures and perceived dysphonia levels (r = 0.34-0.58; p < 0.05).

Conclusion: This research demonstrated that Persian speakers with dysphonia experienced a rise in TAM and a corresponding reduction in CA. In the future, multi-parametric indices can be developed using both TAM and CA to include various aspects of vocal production and yield a single, comprehensive value.