Use of cepstral analysis for differentiating dysphonic from normal voices in children.

OBJECTIVES: Cepstral measures have mainly been evaluated by studies conducted on dysphonic and healthy adults, and many of these studies have reported the advantages of using cepstral measures for the evaluation of dysphonia however there is a paucity regarding to the cepstral analyses' results in dysphonic children. In this present study, it is hypothesized that cepstral peak prominence (CPP) and some other parameters of cepstral analysis would differ in children with vocal nodules when compared with the same parameters of cepstral analysis of healthy children.

METHODS: In this present study, totally 54 children aged between 5 years old to 12 years and 7 months participated. The study group consisted of 20 males and 7 females diagnosed with vocal nodules. The control group consisted of an equal number of age- and gender-matched healthy peers. Analysis of Dysphonia in Speech and Voice software (CSL Model 4500 equipment, Kay Elemetrics Group) was used to gather speech sample recordings according to the Consensus Auditory-Perceptual Evaluation of Voice/Turkish protocol. Cepstral measures of all the six CAPE-V sentences and sustained/a/sample were calculated. CPP, CPP fundamental frequency, CPP standard deviation (CPP SD), Low_high spectral ratio (L/H ratio), L/H ratio standard deviation parameters were taken into account when statistical analyses were completed. In addition to the descriptive statistics of ceptral measures for both groups, the differences between the study and control groups according to the gender were documented.

RESULTS: It was found that for both genders CPP and CPP SD values were significantly higher for the control group for vowel-weighted sample, all voiced-weighted sample, glottal attack-weighted sample, nasal weighted sample, and voiceless-weighted sample. In the vowel-weighted sample, CPP and CPP SD were significantly higher for the control group in males. In females, a difference was only observed on the CPP parameter for the same sentence. In terms of the CPP value of the sustained phonation sample, a significant difference was only detected for males, whereas no difference was detected for females.

CONCLUSIONS: In conclusion, present study found that cepstral analysis can be used to determine the difference between dysphonic and healthy voices of children and indicated that cepstral analysis should be a compulsory component of routine clinical voice evaluation of children. In addition, this present study indicates that of the cepstral analysis of sentences appear to be more sensitive to dysphonia than the analysis of vowel samples. In future studies, normative values of the CAPE-V/Turkish sentences and cutoff values for differentiating dysphonia from normal voice should be evaluated using a larger sample size.