Measures Of Cepstral Peak Prominence Research Articles

Acoustic and Physiologic Correlates of Vocal Effort in Individuals With and Without Primary Muscle Tension Dysphonia.

The aims of this study were to determine relationships between vocal effort and (a) acoustic correlates of vocal output and (b) supraglottic compression in individuals with primary muscle tension dysphonia (pMTD) and without voice disorders (controls) in the context of a vocal load challenge. Twenty-six individuals with pMTD and 35 vocally healthy controls participated in a 30-min vocal load challenge. The pre- and postload relationships among self-ratings of vocal effort, various acoustic voice measures, and supraglottic compression (mediolateral and anteroposterior) were tested with multiple regression models and post hoc Pearson's correlations. Acoustic measures included cepstral peak prominence (CPP), low-to-high spectral ratio, difference in intensity between the first two harmonics, fundamental frequency, and sound pressure level (dB SPL). Regression models for CPP and mediolateral compression were statistically significant. Vocal effort, diagnosis of pMTD, and vocal demand were each significant variables influencing CPP measures. CPP was lower in the pMTD group across stages. There was no statistical change in CPP following the vocal load challenge within either group, but both groups had an increase in vocal effort postload. Vocal effort and diagnosis influenced the mediolateral compression model. Mediolateral compression was higher in the pMTD group across stages and had a negative relationship with vocal effort, but it did not differ after vocal loading. CPP and mediolateral supraglottic compression were influenced by vocal effort and diagnosis of pMTD. Increased vocal effort was associated with lower CPP, particularly after vocal load, and decreased mediolateral supraglottic compression in the pMTD group.

Comparison Between Custom Smartphone Acoustic Processing Algorithms and Praat in Healthy and Disordered Voices

The aim of this study was to understand the relationship between temporal and spectral-based acoustic measures derived using Praat and custom smartphone algorithms across patients with a wide range of vocal pathologies. Voice samples were collected from 56 adults (11 vocally healthy, 45 dysphonic, aged 18-80years) performing three speech tasks: (a) sustained vowel, (b) maximum phonation, and (c) the second and third sentences of the Rainbow passage. Data were analyzed to extract mean fundamental frequency (fo), maximum phonation time (MPT), and cepstral peak prominence (CPP) using Praat and our custom smartphone algorithms. Linear regression models were calculated with and without outliers to determine relationships. Statistically significant relationships were found between the smartphone algorithms and Praat for all three measures (r2 =0.68-0.95, with outliers; r2 =0.80-0.98, without outliers). An offset between CPP measures was found where Praat values were consistently lower than those computed by the smartphone app. Outlying data were identified and described, and findings indicated that speakers with high levels of clinician-perceived dysphonia resulted in smartphone algorithm errors. These results suggest that the proposed algorithms can provide measurements comparable to clinically derived values. However, clinicians should take caution when analyzing severely dysphonic voices as the current algorithms show reduced accuracy for measures of mean fo and MPT for these voice types.

A Practical Guide to Calculating Cepstral Peak Prominence in Praat

The acoustic measure of cepstral peak prominence (CPP) is recommended for the analysis of dysphonia. Yet, clinical use of this measure is not universal, as clinicians and researchers are still learning the strengths and limitations of this measure. Furthermore, affordable access to specialized acoustic software is a significant barrier to universal CPP use. This article will provide a guide on how to calculate CPP in Praat, a free software program, using a new CPP plugin. Important external factors that could influence CPP measures are discussed, and suggestions for clinical use are provided. As CPP becomes more widely used by clinicians and researchers, it is important to consider external factors that may inadvertently influence CPP values. Controlling for these external factors will aid in reducing variability across CPP values, which will make CPP a valuable tool for both clinical and research purposes.

Validation of cepstral peak prominence in assessing early voice changes of Parkinson's disease: Effect of speaking task and ambient noise.

Although the cepstral peak prominence (CPP) and its variant, the cepstral peak prominence smooth (CPPS), are considered to be robust acoustic measures for the evaluation of dysphonia, whether they are sensitive to capture early voice changes in Parkinson's disease (PD) has not yet been explored. This study aimed to investigate the voice changes via the CPP measures in the idiopathic rapid eye movement sleep behavior disorder (iRBD), a special case of prodromal neurodegeneration, and recently diagnosed and advanced-stage Parkinson's disease (AS-PD) patients using different speaking tasks across noise-free and noisy environments. The sustained vowel phonation, reading of passages, and monologues of 60 early stage untreated PD, 30 advanced-stage Parkinson's disease, 60 iRBD, and 60 healthy control (HC) participants were evaluated. Significant differences were found between the PD groups and controls in sustained phonation via the CPP (p < 0.05) and CPPS (p < 0.01) and the monologue via the CPP (p < 0.01), although neither the CPP nor CPPS measures were sufficiently sensitive to capture the possible prodromal dysphonia in the iRBD. The quality of the CPP and CPPS measures was influenced substantially by the addition of ambient noise. It was anticipated that the CPP measures might serve as a promising digital biomarker in assessing the dysphonia from the early stages of PD.

Characterization of Dermatoglyphic Profiles and its Relation to Acoustic Measures in Voice Professionals

IntroductionAcoustic analysis is widely used for assessing and monitoring vocal function. Dermatoglyphics is a method that analyzes genetic fingerprint markers, and uses that information for predicting physical skills related to anaerobic (explosive strength and speed) and aerobic (motor coordination and resistance) mechanisms. Therefore, it can be used as an indicator for individualized vocal training. ObjectiveTo characterize the dermatoglyphic profiles and their relation to acoustic measures in voice professionals. MethodsA cross-sectional study involving 79 voice professionals. Acoustic analysis was performed using the PRAAT software. Mean intensity, fundamental frequency (F0), and cepstral peak prominence (CPP) value were extracted from the sustained vowel /a/. Fingerprints were collected using a Watson mini-integrated biometric scanner, and were quantified by design predominance, delta index (D10), total ridge count (TRC), and dermatoglyphic profile. The acoustic measures were analyzed descriptively and compared, considering the subjects’ dermatoglyphic profiles. The confidence levels ranged from 90% to 95%. ResultsMost subjects exhibited anaerobic dermatoglyphic profiles (P = 0.004) and low TRC (p < 0.001). Higher F0 (P = 0.061), intensity (P = 0.065), and CPP (P = 0.073) were found for anaerobics (P < 0.001). There was a weak and negative correlation between TRC and intensity (P = 0.026), as well as between F0 (P = 0.017) and CPP (P = 0.069). ConclusionAnaerobic profiles were predominant. The values of F0, intensity, and CPP increased for the anaerobics. There was a weak negative correlation between the TRC and intensity, F0, and CPP measures. Dermatoglyphics could have been seen as an interesting tool in the voice assessment and training direction for voice professionals.

Relating Cepstral Peak Prominence to Cyclical Parameters of Vocal Fold Vibration from High-Speed Videoendoscopy Using Machine Learning: A Pilot Study

Smoothed cepstral peak prominence (CPPs) has been shown to be an effective indicator of breathiness (Hillenbrand and Houde, 1996). High-speed videoendoscopy (HSV) is frequently being used as a complement to stroboscopy especially when asymmetric or aperiodic vocal fold vibration is present in dysphonic voices. In an HSV image data set obtained with normal (nondisordered) voice subjects, we have observed that some degree of asymmetry is present in many of the vocal fold displacement curves extracted from the HSV exam videos; therefore, we have used this data set for a pilot study to investigate the relationship of CPPs to cyclical vocal fold vibration parameters, including left-right vocal fold (LVRF) phase asymmetry, in subjects with normal (nondisordered) voices. Twenty subjects with normal (nondisordered) voices produced sustained vowel phonations while undergoing a transoral HSV examination of the vocal folds with synchronized recording of the voice signal. Glottal area waveform (GAW) and cyclical parameters open quotient (OQ), closed quotient (CQ), speed quotient (SQ), and LVRF skew were extracted from the HSV exam videos, and CPPs measures were obtained from acoustic analysis of the audio recordings. Correlations among the cyclical parameters and CPPs values were investigated using machine learning with the Regression Learner application in the MATLAB© Statistics and Machine Learning Toolbox (version 9.5.0.944444, R2018b, August 28, 2018, (c) 1984-2018, The MathWorks, Inc., Natick, MA). Because the sample size of the data set used for this study was small, and because there possibly was multicollinearity among the predictor variables used, the only meaningful result that was obtained with the data set of 20 normal subjects in the four predictor variables was the constant model (ie, the best prediction of CPPs was just the average value of the 20 observations), when the model validation feature of the app was turned on to protect against overfitting. In order to fully investigate the usefulness of the Regression Learner App, however, the validation feature was turned off and 48 more model types were investigated. While these were not necessarily indicative of the best regression model for the current data set, the results obtained in this manner nevertheless demonstrated the utility of the automated approach for finding a regression model for a larger data set to be collected in the future. Further work is warranted to collect a data set from a larger sample size of disordered voice patients with breathy and/or rough voice. It is speculated that a correlation between CPPs and cyclical parameters of vocal fold vibration may be more evident with disordered voices, because there will be more asymmetry in LRVF displacement with an effect on the acoustic voice signal.

Glottal Source Analysis of Voice Deficits in Newly Diagnosed Drug-naïve Patients with Parkinson’s Disease: Correlation Between Acoustic Speech Characteristics and Non-Speech Motor Performance

As dysphonia is assumed to be the most prevalent feature of hypokinetic dysarthria in Parkinson’s disease (PD), several acoustic approaches have been introduced for its assessment. However, the sensitivity of different acoustic measures to the occurrence of dysphonia in drug-naïve de-novo patients with PD has not yet been explored. The goal of this study is to examine the performance of glottal source parametrization and compare it with traditional perturbation and cepstral measures. Sustained phonations of 40 de-novo drug-naïve PD participants and 40 age- and sex-matched healthy controls were recorded. Each utterance was ranked by a set of glottal source parameters obtained by inverse adaptive filtering, the perturbation parameters, and cepstral peak prominence measures. Our results revealed the significant differences in the glottal source parameter Harmonic Richness Factor (HRF: p < 0.01) and cepstral peak prominence parameter (p < 0.05). The support vector machine classification between PD and healthy controls reached the area under the curve of 0.78. The analysis of relationships showed significant negative correlations between HRF and total Movement Disorders Society – Unified Parkinson’s Disease Rating Scale III score (r=-0.35, p < 0.05), as well as its rigidity (r=-0.43, p < 0.01) and bradykinesia (r=-0.32, p < 0.05) sub-scores. Glottal source assessment appears to be a superior method to assess PD-related dysphonia compared to the traditional perturbation and cepstral approaches. Our results highlight that dysphonia and limb bradykinesia and rigidity in PD are controlled by similar underlying brain processes.

Validation of the Measures of Cepstral Peak Prominence as a Measure of Dysphonia Severity in Spanish-Speaking Subjects

Introduction and objectivesPerceptual rating of overall voice quality and other more specific perceptual dimensions is difficult, as such judgments depend on the listener's subjectivity. Thus, finding objective, valid, and accessible clinical measures to include in comprehensive voice evaluation protocols is a priority.The purposes of this study were to (1) determine the diagnostic accuracy of a single acoustic measure, smoothed cepstral peak prominence (CPPS), to predict voice disorder status from sustained vowels and connected speech samples using the software Praat; (2) to determine the relationship between measures of CPPS and perceptual ratings of vocal quality; and (3) describe the normative values of CPPS. MethodMeasures of CPPS were obtained from connected speech and sustained vowel recordings of 72 Spanish-speaking subjects with voice disorders and 52 nondysphonic Spanish-speaking subjects with no vocal disorders using freely downloadable Praat software. IBM SPSS Statistics software version 23 was used to complete the statistical analyses. ResultsResults revealed a 70% sensitivity rate, a specificity rate of 85%. Estimated severity for sustained vowels and connected speech were strongly correlated and significantly associated with listener ratings of dysphonia severity. ConclusionsA single acoustic measure of CPPS was highly predictive of voice disorder status using Praat software. Clinicians may consider using CPPS to complement clinical voice evaluation and screening protocols.

The Effect of Parkinson Disease Tremor Phenotype on Cepstral Peak Prominence and Transglottal Airflow in Vowels and Speech

The physiological manifestations of Parkinson disease are heterogeneous, as evidenced by disease subtypes. Dysphonia has been well documented as an early and progressively significant impairment associated with the disease. The purpose of this study was to investigate how acoustic and aerodynamic measures of vocal function were affected by Parkinson tremor subtype (phenotype) in an effort to better understand the heterogeneity of voice impairment severity in Parkinson disease. This is a prospective case-control study. Thirty-two speakers with Parkinson disease assigned to tremor and nontremor phenotypes and 10 healthy controls were recruited. Sustained vowels and connected speech were recorded from each speaker. Acoustic measures of cepstral peak prominence (CPP) and aerodynamic measures of transglottal airflow (TAF) were calculated from the recorded acoustic and aerodynamic waveforms. Speakers with a nontremor dominant phenotype exhibited significantly (P < 0.05) lower CPP and higher TAF in vowels compared with the tremor dominant phenotype and control speakers, who were not different from each other. No significant group differences were observed for CPP or TAF in connected speech. When producing vowels, participants with nontremor dominant phenotype exhibited reduced phonation periodicity and elevated TAF compared with tremor dominant and control participants. This finding is consistent with differential limb-motor and cognitive impairments between tremor and nontremor phenotypes reported in the extant literature. Results suggest that sustained vowel production may be sensitive to phonatory control as a function of Parkinson tremor phenotype in mild to moderate stages of the disease.

Vocal Loading and Environmental Humidity Effects in Older Adults

Thirteen healthy subjects (five males and eight females; >65 years) completed a vocal loading challenge. The challenge involved 45 minutes of child-directed speech in the presence of 65 dB multitalker babble background noise. Subjects completed this challenge in both low humidity and moderate humidity in counterbalanced order. Vocal function was assessed before and after the challenge using phonation threshold pressure (PTP), cepstral peak prominence (CPP), low/high spectral ratio (LHR), perceived phonatory effort (PPE), and perceived vocal tiredness. Negative changes were observed in the aging larynx following the 45-minute vocal loading challenge. Measures of PTP, PPE, and perceived vocal tiredness demonstrated statistically significant loading effects. Increased ambient humidity significantly alleviated the negative changes observed in PPE and perceived vocal tiredness. Increased humidity significantly improved CPP measures both before and after the vocal loading challenge. This study furthers our understanding of how older adults respond to a vocal loading challenge of prolonged nonhabitual speech in a noisy environment. Our data suggest that the aging voice is negatively affected by prolonged loud speaking and that humidification may be beneficial in reducing some of these negative effects.

Predicting Voice Disorder Status From Smoothed Measures of Cepstral Peak Prominence Using Praat and Analysis of Dysphonia in Speech and Voice (ADSV)

The purposes of this study were to (1) determine and compare the diagnostic accuracy of a single acoustic measure, smoothed cepstral peak prominence (CPPS), to predict voice disorder status from connected speech samples using two software systems: Analysis of Dysphonia in Speech and Voice (ADSV) and Praat; and (2) to determine the relationship between measures of CPPS generated from these programs. This is a retrospective cross-sectional study. Measures of CPPS were obtained from connected speech recordings of 100 subjects with voice disorders and 70 nondysphonic subjects without vocal complaints using commercially available ADSV and freely downloadable Praat software programs. Logistic regression and receiver operating characteristic (ROC) analyses were used to evaluate and compare the diagnostic accuracy of CPPS measures. Relationships between CPPS measures from the programs were determined. Results showed acceptable overall accuracy rates (75% accuracy, ADSV; 82% accuracy, Praat) and area under the ROC curves (area under the curve [AUC] = 0.81, ADSV; AUC = 0.91, Praat) for predicting voice disorder status, with slight differences in sensitivity and specificity. CPPS measures derived from Praat were uniquely predictive of disorder status above and beyond CPPS measures from ADSV (χ2(1) = 40.71, P < 0.001). CPPS measures from both programs were significantly and highly correlated (r = 0.88, P < 0.001). A single acoustic measure of CPPS was highly predictive of voice disorder status using either program. Clinicians may consider using CPPS to complement clinical voice evaluation and screening protocols.

A Comparison of Cepstral Peak Prominence Measures From Two Acoustic Analysis Programs

This study aimed to investigate the relationship and reliability of cepstral peak prominence (CPP) measures from two acoustic software applications, Analysis of Dysphonia in Speech and Voice (ADSV) and Praat. Flemish and English recordings of sustained vowels and connected speech samples were analyzed using ADSV and Praat. Correlational analyses and measures of the standard error of the estimate were applied to the vowel and connected speech data obtained from the two programs. Analyses revealed very strong relationships (eg, r > 0.88) between CPP measures derived from ADSV and those derived from Praat, regardless of context (vowel or connected speech) or language spoken. Average residual errors ranged from 0.55 to 1.1 dB for the prediction of Praat CPP data from actual observed ADSV CPP data, and average residual errors ranged from 0.57 to 1.58 dB for the prediction of ADSV CPP data from actual observed Praat CPP data. Measurements of CPP derived from ADSV and Praat manifested strong parallel-forms reliability. Although CPP data values obtained via these programs will be different owing to algorithmic processing differences, this study found that estimated CPP values derived using regression equations could be transformed between programs with relatively small predictive error, regardless of language. The strong measurement relationships indicate that CPP values from either program have a high degree of shared variance and may be expected to differentiate across a wide range of voice signal periodicity in a relatively similar fashion. This finding supports the use of either program in clinical use and voice science research.

Acoustic and Perceptual Classification of Within-sample Normal, Intermittently Dysphonic, and Consistently Dysphonic Voice Types

Intermittent dysphonia within an utterance is common, but presents difficulty for both perceptual and objective voice evaluation. This study examined the ability of measures from the within-sample cepstral peak prominence (CPP) distribution to differentiate normal voices from intermittently and consistently dysphonic voices. Exploratory design. Sixty samples of the sentence "We were away a year ago" were classified as normal, intermittently dysphonic, or consistently dysphonic by four judges. Measures of CPP within each sample were obtained, and further analysis with examined CPP distribution variability and patterns of CPP outliers. Whereas the mean CPP was the strongest single discriminator among the three voice types, the normal and intermittent dysphonia groups were not significantly different on CPP distribution skewness and measures of CPP distribution outliers. Both the normal and intermittently dysphonic voices differed significantly from the consistently dysphonic samples on these variables. A combination of measures of the CPP distribution was effective for a linear prediction of percent dysphonia duration for the speech samples (r = 0.825; rho = 0.81). The CPP standard deviation significantly improved the use of the mean CPP in discriminant function analyses and also the classification of the intermittently dysphonic voices. Auditory-perceptual judgment of dysphonic segments and the typically robust acoustic measurement of mean CPP are both ineffective for classifying intermittently dysphonic voices. However, dysphonia duration may be effectively predicted via measures of the CPP distribution, and acoustic classification of dysphonic voice types via cepstral methods may be improved with an analysis of the CPP distribution across an utterance.

The Effect of CAPE-V Sentences on Cepstral/Spectral Acoustic Measures in Dysphonic Speakers

Objective: To investigate the effect of connected speech stimuli from the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) on cepstral/spectral acoustic measurements. Patients and Methods: Recordings from 20 participants seeking treatment for dysphonia were analyzed in this study. The participants read the 6 sentence stimuli from the CAPE-V at a comfortable pitch and loudness. Acoustic measures of cepstral peak prominence (CPP) and its standard deviation, the low-to-high spectral ratio and its standard deviation (LH and LHsd) and the multiparametric measure Cepstral Spectral Index of Dysphonia were acquired from each sentence recording and applied to analyses. Results: A significant main effect for sentence type was present on the measurements of CPP, LH and LHsd. Post hoc pairwise comparisons revealed the most robust effect on CPP from the all-voiced sentence ‘We were away a year ago'. For the measures of LH and LHsd, sentence effects were significant for the majority of comparisons. Conclusion: The connected speech stimuli from the CAPE-V affected cepstral/spectral acoustic measurements differentially. These findings support the rationale for using the various CAPE-V stimuli during clinical assessment, and indicate the need for further investigations to inform clinical practice.

Cepstral Analysis of Hypokinetic and Ataxic Voices: Correlations With Perceptual and Other Acoustic Measures

To investigate the validity of cepstral analyses against other conventional acoustic measures of voice quality in determining the perceptual impression in different motor speech disorders-hypokinetic and ataxic dysarthria, and speech tasks-prolonged vowels and connected speech. Prolonged vowel productions and connected speech samples (reading passages and monologues) from 43 participants with Parkinson disease and 10 speakers with ataxia were analyzed perceptually by a trained listener using GRBAS. In addition, acoustic measures of cepstral peak prominence (CPP), smoothed CPP (CPPs), harmonics-to-noise ratio (HNR), shimmer %, shimmer dB, amplitude perturbation quotient (APQ), relative average perturbation (RAP), jitter, and pitch perturbation quotient (PPQ) were performed. Statistical analysis involved correlations between perceptual and acoustic measures, as well as determination of differences across speaker groups and elicitation tasks. CPP and CPPs results showed greater levels of correlation with overall dysphonia, breathiness, and asthenia ratings than the other acoustic measures, except in the case of roughness. Sustained vowel production produced a higher number of significant correlations across all parameters other than connected speech, but task choice did not affect CPP and CPPs results. There were no significant differences in any parameters across the two speaker groups. The results of this study are consistent with the results of other studies investigating the same measures in speakers with nonmotor-related voice pathologies. In addition, there was an indication that they performed better in relation to asthenia, which might be particularly relevant for the current speaker group. The results support the clinical and research use of CPP and CPPs as a quantitative measure of voice quality in populations with motor speech disorder.

Aerodynamic and Acoustic Features of Vocal Effort

The purpose of this study was to determine the aerodynamic and acoustic features of speech produced at comfortable, maximal and minimal levels of vocal effort. Prospective, quasi-experimental research design. Eighteen healthy participants with normal voice were included in this study. After task training, participants produced repeated syllable combinations at comfortable, maximal and minimal levels of vocal effort. A pneumotachometer and vented (Rothenberg) mask were used to record aerodynamic data, with simultaneous recording of the acoustic signal for subsequent analysis. Aerodynamic measures of subglottal pressure, translaryngeal airflow, maximum flow declination rate (MFDR), and laryngeal resistance were analyzed, along with acoustic measures of cepstral peak prominence (CPP) and its standard deviation (SD). Participants produced significantly greater subglottal pressure, translaryngeal airflow, and MFDR during maximal effort speech as compared with comfortable vocal effort. When producing speech at minimal vocal effort, participants lowered subglottal pressure, MFDR, and laryngeal resistance. Acoustic changes associated with changes in vocal effort included significantly higher CPP during maximal effort speech and significantly lower CPP SD during minimal effort speech, when each was compared with comfortable effort. For healthy speakers without voice disorders, subglottal pressure, translaryngeal airflow, and MFDR may be important factors that contribute to an increased sense of vocal effort. Changes in the cepstral signal also occur under conditions of increased or decreased vocal effort relative to comfortable effort.

Acoustic Characteristics of Male Commercial and Public Radio Broadcast Voices

Radio broadcasters need to have a voice that suits the station, which employs them. The aim of this study was to determine whether there are any acoustic measures that reflect differences between male broadcasters, who use their voices on commercial and public radio stations, and nonbroadcasting, male controls. Male commercial (n = 4) and public (n = 11) broadcasters and two groups of male, age-matched controls were recorded while reading the "Rainbow Passage" as if presenting on radio. Reading productions were analyzed for equivalent sound level (L(eq)), two measures of the long-term average spectrum and two measures of cepstral peak prominence. A two-group (ie, commercial vs public) by two-paired (broadcaster/matching control) analysis of variance was performed for each measure. An interaction effect was observed such that commercial broadcasters had a higher peak in speaker's formant (SF) region and lower alpha ratio (AR) (lower level difference between 0 and 1 k Hz and 1 and 4 kHz ranges) than public broadcasters and controls. Post hoc discriminant function analyses showed that AR could predict whether a radio performer worked on commercial or public radio network to 81% accuracy (R(2) = 0.810, P < 0.001). Commercial broadcasters have a more prominent peak in the SF region and smaller AR than public broadcasters and controls, similar to levels documented in actors. Given these features were not found in the public broadcasters and either control group, these results indicate that voice quality requirements for broadcasters may distinctly differ based on their station of employment. Further research with a larger sample size is required to validate this hypothesis.

Use of Spectral/Cepstral Analyses for Differentiating Normal From Hypofunctional Voices in Sustained Vowel and Continuous Speech Contexts

In this study, the authors evaluated the diagnostic value of spectral/cepstral measures to differentiate dysphonic from nondysphonic voices using sustained vowels and continuous speech samples. Thirty-two age- and gender-matched individuals (16 participants with dysphonia and 16 controls) were recorded reading a standard passage (The Rainbow Passage; Fairbanks, 1960) and sustaining the vowel /α/. Recorded voices were analyzed with custom software that calculated 4 spectral/cepstral measures. Measures of cepstral peak prominence (CPP) and low-high spectral ratio (L/H ratio) were significantly different between groups in both speaking conditions; the standard deviation of the CPP was significantly different between groups in continuous speech only. In differentiating dysphonic individuals with a hypofunctional etiology from nondysphonic individuals, receiver operating characteristic (ROC) analyses demonstrated (a) high sensitivity and high specificity for the CPP in the sustained vowel condition and (b) high sensitivity and moderate specificity for the CPP in the speech condition. In a sample of dysphonic speakers (hypofunctional etiologies) versus typical speakers, spectral/cepstral measures of CPP and L/H ratio were able to differentiate these groups from one another in both vowel prolongation and continuous speech contexts with high sensitivity and specificity. The results of this study support the growing body of literature documenting the significant value of cepstral and other spectral-based acoustic measures to the clinical evaluation and management processes.

Spectral- and Cepstral-Based Measures During Continuous Speech: Capacity to Distinguish Dysphonia and Consistency Within a Speaker

Spectral- and cepstral-based acoustic measures are preferable to time-based measures for accurately representing dysphonic voices during continuous speech. Although these measures show promising relationships to perceptual voice quality ratings, less is known regarding their ability to differentiate normal from dysphonic voice during continuous speech and the consistency of these measures across multiple utterances by the same speaker. The purpose of this study was to determine whether spectral moments of the long-term average spectrum (LTAS) (spectral mean, standard deviation, skewness, and kurtosis) and cepstral peak prominence measures were significantly different for speakers with and without voice disorders when assessed during continuous speech. The consistency of these measures within a speaker across utterances was also addressed. Continuous speech samples from 27 subjects without voice disorders and 27 subjects with mixed voice disorders were acoustically analyzed. In addition, voice samples were perceptually rated for overall severity. Acoustic analyses were performed on three continuous speech stimuli from a reading passage: two full sentences and one constituent phrase. Significant between-group differences were found for both cepstral measures and three LTAS measures (P<0.001): spectral mean, skewness, and kurtosis. These five measures also showed moderate to strong correlations to overall voice severity. Furthermore, high degrees of within-speaker consistency (correlation coefficients ≥0.89) across utterances with varying length and phonemic content were evidenced for both subject groups.

An acoustic and electroglottographic study of phonation contrast in Yi.

This study examines the phonation contrast of Yi, a Tibeto-Burman language of Southwestern China with phonation as a phonemic dimension (traditionally described as tense versus lax contrast). The language has seven monophthongs as well as three tones (high, mid, and low). Tense versus lax phonation contrast can apply to all the vowels and two tones (mid and low) in the language. In this study, both acoustic and electroglottographic data were collected with minimal pairs for all combinations of tones and vowels. Extensive acoustic measures were done by VOICESAUCE, including F0, H1, H2, H1-H2, H2-H4, H1-A1, H1-A2, F1, F2, and cepstral peak prominence (CPP); EGG measures were closed quotient (CQ) and peak-velocity (PV). Preliminary data suggest that H1-H2, CPP, CQ, and PV measures can exclusively distinguish the two phonation types. Moreover, EGG data also suggest voice quality interacts with tones, but the patterns vary among speakers. This might due to the different strategies used by speakers to produce the tense versus lax contrast. In addition, formant frequency measures also show salient differences between tense and lax vowels; tense vowels generally have higher F1 than the lax counterparts. All of the facts suggest that phonation contrasts in Yi are realized across different phonetic dimensions.