Cepstral analysis of normal and pathological voice in Spanish adults. Smoothed cepstral peak prominence in sustained vowels versus connected speech.

INTRODUCTION AND OBJECTIVES

In recent years, the use of cepstral measures for acoustic evaluation of voice has increased. One of the most investigated parameters is smoothed cepstral peak prominence (CPPs). The objectives of this paper are to establish the usefulness of this acoustic measure in the objective evaluation of alterations of the voice in Spanish and to determine what type of voice sample (sustained vowels or connected speech) is the most sensitive in evaluating the severity of dysphonia.

METHOD

Forty subjects participated in this study 40, 20 controls and 20 with dysphonia. Two voice samples were recorded for each subject (one sustained vowel/a/and four phonetically balanced sentences) and the CPPs was calculated using the Praat programme. Three raters perceptually evaluated the voice sample with the Grade parameter of GRABS scale.

RESULTS

Significantly lower values were found in the dysphonic voices, both for/a/(t= 4.85, P<.000) and for phrases (t = 5,75, P<.000). In relation to the type of voice sample most suitable for evaluating the severity of voice alterations, a strong correlation was found with the acoustic-perceptual scale of CPPs calculated from connected speech (r = -0.73) and moderate correlation with that calculated from the sustained vowel (r = -0,56).

CONCLUSION

The results of this preliminary study suggest that CPPs is a good measure to detect dysphonia and to objectively assess the severity of alterations in the voice.