Retrospective data analysis.
Seventy-three hoarse patients (48.3 ¡À 16.8 years) uttered the vowel /e/ and read the German version of the text ¡°The North Wind and the Sun¡±. The text recordings were evaluated perceptually by five speech therapists and physicians according to the RBH scale. The criterion ¡°overall quality¡± was measured on a 4-point scale and a visual analog scale. For the human-machine correlation, the automatic measures of the Praat program (vowels only) and the ¡°cpps¡± software were compared with the experts' ratings. The experiments were repeated for speakers with jitter ¡Ü5 % or shimmer ¡Ü5 % (n = 47).
For the entire group (n = 73), the best human-machine results for most of the rating criteria were obtained for text-based CPP and CPPS (up to |¦Ñ| = 0.73). For the 47 selected speakers, the correlation was remarkably worse for all measures but still best for text-based CPP and CPPS (|¦Ñ| ¡Ü 0.50).
Cepstrum analysis should be performed on a text recording. Then, it outperforms all perturbation-based measures, and it can be a meaningful objective support for perceptual analysis.