Fundamental Frequency and Intensity Effects on Cepstral Measures in Vowels from Connected Speech of Speakers with Voice Disorders.

OBJECTIVE: Cepstral peak prominence (CPP) and smoothed CPP (CPPS) have been described as reliable parameters to detect overall dysphonia in standardized connected speech samples. Recent studies indicate that vocal intensity (sound pressure level, SPL) and fundamental frequency (fo) changes may influence cepstral measurement results in healthy speakers. The main aim of the present work was to investigate the effects of prosody related SPL and fo variations on cepstral measures in speech of adults with voice disorders. STUDY DESIGN: Retrospective cross-sectional study. METHODS: Recordings of CAPE-V sentences from 27 voice disordered Brazilian Portuguese speakers (19 women, eight men) with a mean age of 45 years (SD = 13) were investigated. Five /a/ vowels were manually extracted from stressed syllables in different positions. Voice fo (Hz), SPL (dBA), CPP (dB), and CPPS (dB) were computed using PRAAT. Statistical analysis included Linear Mixed Models with ANCOVA and Bonferroni post hoc tests. RESULTS: Voice SPL as single factor and combined with fo had a highly significant effect (P ≤ 0.001), while fo alone had no significant impact on both CPP and CPPS (P ≥ 0.77). Voice fo, SPL, CPP, and CPPS of the first vowel were all significantly lower than of the last vowel (P ≤ 0.03). CONCLUSION: In vowel samples from connected speech of adults with voice disorders, we observed better CPP and CPPS in higher voice SPL alone and combined with higher fo. Further, the vowel position influenced the present results. A larger clinical study should confirm how prosody related SPL and fo and vowel position effects could be controlled for in connected speech samples.

Effects of Fundamental Frequency, Vocal Intensity, Sample Duration, and Vowel Context in Cepstral and Spectral Measures of Dysphonic Voices.

Purpose Smoothed cepstral peak prominence (CPPS) and harmonics-to-noise ratio (HNR) are acoustic measures related to the periodicity, harmonicity, and noise components of an acoustic signal. To date, there is little evidence about the advantages of CPPS over HNR in voice diagnostics. Recent studies indicate that voice fundamental frequency (F0) and intensity (sound pressure level [SPL]), sample duration (DUR), vowel context (speech vs. sustained phonation), and syllable stress (SS) may influence CPPS and HNR results. The scope of this work was to investigate the effects of voice F0 and SPL, DUR, SS, and token on CPPS and HNR in dysphonic voices. Method In this retrospective study, 27 Brazilian Portuguese speakers with voice disorders were investigated. Recordings of sustained vowels (SVs) /a:/ and manually extracted vowels (EVs) /a/ from Consensus Auditory-Perceptual Evaluation of Voice sentences were acoustically analyzed with the Praat program. Results There was a highly significant effect of F0, SPL, and DUR on both CPPS and HNR (p < .001), whereas SS and vowel context significantly affected CPPS only (p < .05). Higher SPL, F0, and lower DUR were related to higher CPPS and HNR. SVs moderately-to-highly correlated with EVs for CPPS, whereas HNR had few and moderate correlations. In addition, CPPS and HNR highly correlated in SVs and seven EVs (p < .05). Conclusion Speaking prosodic variations of F0, SPL, and DUR influenced both CPPS and HNR measures and led to acoustic differences between sustained and excised vowels, especially in CPPS. Vowel context, prosodic factors, and token type should be controlled for in clinical acoustic voice assessment.

Reliable acoustic measurements in children between 5;0 and 9;11 years: Gender, age, height and weight effects on fundamental frequency, jitter and shimmer in phonations without and with controlled voice SPL.

BACKGROUND: Current pediatric voice assessment guidelines include instrumental measurements of fundamental frequency (F0) and the perturbation indices jitter and shimmer. In children below 10 years, gender, age, height and weight effects on these parameters have been inconsistently characterized. Recent research in healthy children showed, that differences in habitual speaking voice intensity (voice SPL) under the usual assessment procedure significantly affect jitter and shimmer. These effects were reduced in phonations with controlled voice SPL >80dBA. Reliable measurement methods and description of physiologic influencing factors are essential to identify pathologic voices. OBJECTIVE: This cross-sectional single cohort study investigates in children between 5;0 and 9;11 years how gender, age, height and weight affect voice F0, jitter and shimmer in phonations at individually "medium" voice intensity (modeling the usual clinical practice) and with controlled voice SPL >80dBA. SUBJECTS AND METHODS: 68 vocally healthy children (39 f/29 m) aged 5;0-9;11 years provided 3 prolonged phonations of/a/at individually "medium" and controlled voice intensity at ">80dBA" (visual feedback, 10cm distance). F0 (Hz), jitter (%), shimmer (%) and voice SPL (dBA) were determined with PRAAT. Gender, age, height and weight effects without and with controlled voice SPL were assessed by descriptive statistics, Analysis of Variance and Linear Mixed Models. RESULTS: F0 (Hz), jitter (%), shimmer (%) and voice SPL (dBA) were significantly different in medium voice compared to >80dBA (p<0.01). In medium phonations girls had a higher F0 than boys (girls: 276.7(50.7), boys: 261.5(33.7)), but with >80dBA this difference was only minimal (girls: 328.9(52.2), boys 327.9(51.2)). Mean jitter (0.27(0.10)) and shimmer (4.34(1.68)) were smaller and showed less spread (jitter: 0.5(0.26); shimmer: 9.47(3.47)) with >80dBA. Gender, age, height and weight had no significant effects on F0, jitter, shimmer and voice SPL in both phonation types (p-range=0.42-0.99). CONCLUSIONS: Neither without nor with controlled voice SPL there were systematic gender, age, height or weight effects on voice F0, jitter and shimmer. Gender related F0 discrepancies were equalized in phonations with >80dBA. In children below 10 years gender related acoustic voice differences may be mainly linked to behavior, which should be considered in future works regarding physiologic voice development.

Clinical relevance of speaking voice intensity effects on acoustic jitter and shimmer in children between 5;0 and 9;11 years.

BACKGROUND: Current voice assessment recommendations for dysphonic children comprise instrumental acoustic measurements of the perturbation parameters jitter and shimmer. In healthy adults and children changes in speaking voice sound pressure level (voice SPL) have significant confounding effects on both parameters. In adults these effects were considerably reduced in phonations with controlled voice SPL >80dBA (10cm distance). However, it is unclear if these findings apply to children and if children are able to control for their own voice intensity. OBJECTIVE: This cross-sectional single cohort study investigates voice SPL effects on jitter and shimmer in children between 5;0 and 9;11 years phonating at individually "medium" (modeling "comfortable" loudness of the usual clinical protocol), "soft" and "loud" voice and a prescribed intensity level of ">80dBA" (10cm distance, with visual control). Further both their ability to phonate at a prescribed voice intensity level and the effect on SPL related confounding effects were studied. SUBJECTS AND METHODS: A total of 68 healthy children (39 f/29m) aged 5;0 to 9;11 years were included. All phonated the vowel/a/for 5s, three times at four defined voice intensity levels (soft/medium/loud/>80dBA) each. Jitter (%), shimmer (%) and voice SPL (dBA) were determined using PRAAT. Voice intensity level effects were assessed by descriptive statistics, Analysis of Variance (ANOVA) and Linear Mixed Models (LMM). RESULTS: There were significant differences for jitter and shimmer between all voice tasks (p<.01). Jitter and shimmer were lowest and showed the smallest spread in controlled phonations ">80dBA". 19 children below 7;0 years could not perform the voice tasks and were excluded from the study. CONCLUSIONS: This practical study demonstrated a significant effect of voice loudness and task on jitter and shimmer in children. Since the observed confounding effects were large compared to treatment effects, jitter and shimmer may not be meaningful without adequate control of voice SPL. In phonations at ">80dBA" (10cm distance) voice SPL related effects were considerably reduced. However, this assessment protocol was suitable only for children above 7;0 years. Application of this task to future studies of dysphonic children may yield clinically valuable information.