Effects of simulated source of tremor on acoustic and airflow voice measures (original) (raw)
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Acoustic Characteristics of Simulated Respiratory-Induced Vocal Tremor
American Journal of Speech-Language Pathology, 2013
Purpose The purpose of this study was to investigate the relation of respiratory forced oscillation to the acoustic characteristics of vocal tremor. Method Acoustical analyses were performed to determine the characteristics of the intensity and fundamental frequency (F 0 ) for speech samples obtained by Farinella, Hixon, Hoit, Story, and Jones (2006) using a respiratory forced oscillation paradigm with 5 healthy adult males to simulate vocal tremor involving respiratory pressure modulation. The analyzed conditions were sustained productions of /a/ with amplitudes of applied pressure of 0, 1, 2, and 4 cmH 2 O and a rate of 5 Hz. Results Forced oscillation of the respiratory system produced modulation of the intensity and F 0 for all participants. Variability was observed between participants and conditions in the change in intensity and F 0 per unit of pressure change, as well as in the mean intensity and F 0 . However, the extent of modulation of intensity and F 0 generally increase...
Physiologic and Acoustic Patterns of Essential Vocal Tremor
Journal of Voice, 2013
Objectives/Hypothesis. This article describes a case study of physiologic and acoustic patterns of essential vocal tremor (EVT). Simulations of vocal tremor were used to test hypotheses regarding measured acoustic patterns and expected physiologic sources. Study Design. This is a case study of EVT using an analysis by synthesis approach. Methods. Oscillations of vocal tract and laryngeal structures were identified using rigid videostroboscopic examination. Acoustical analyses of sustained phonation were completed using the methods previously described in the literature and custom-written MATLAB functions. Simulations of the client's vocal tremor were created using a computational model. Results. The client exhibited vocal fold length changes and oscillation within the laryngeal vestibule during sustained phonation at a comfortable pitch and loudness. Despite the involvement of vocal fold length changes, a low average extent of fundamental frequency (F 0) modulation (ie, 5.3%) and high average extent of intensity modulation (ie, 23.0%) were measured. Simulations of vocal tremor involving modulation of F 0 demonstrated that this source of tremor contributes to frequency-induced intensity modulation, although there was a greater extent of F 0 modulation than intensity modulation. Conclusions. The greater extent of intensity than F 0 modulation in one client with EVT exhibiting predominant vocal fold length changes contrasted with the lower extent of intensity than F 0 modulation in simulated vocal tremor involving F 0 modulation. These findings demonstrate that other potential sources of intensity modulation outside the larynx should be determined during the evaluation of clients with vocal tremor.
Vocal tremors characterize many pathological voices, but acoustic-perceptual aspects of tremor are poorly understood. To investigate this relationship, 2 tremor models were implemented in a custom voice synthesizer. The first modulated fundamental frequency (F0) with a sine wave. The second provided irregular modulation. Control parameters in both models were the frequency and amplitude of the F0 modulating waveform. Thirty-two 1-s samples of /a/, produced by speakers with vocal pathology, were modeled in the synthesizer. Synthetic copies of each vowel were created by using tremor parameters derived from different features of F0 versus time plots of the natural stimuli or by using parameters chosen to match the original stimuli perceptually. Listeners compared synthetic and original stimuli in 3 experiments. Sine wave and irregular tremor models both provided excellent matches to subsets of the voices. The perceptual importance of the shape of the modulating waveform depended on the severity of the tremor, with the choice of tremor model increasing in importance as the tremor increased in severity. The average frequency deviation from the mean F0 proved a good predictor of the perceived amplitude of a tremor. Differences in tremor rats were easiest to hear when the tremor was sinusoidal and of small amplitude. Differences in tremor rate were difficult to judge for tremors of large amplitude or in the context of irregularities in the pattern of frequency modulation. These results suggest that difference limens are larger for modulation rates and amplitudes when the tremor pattern is complex. Further, tremor rate, regularity, and amplitude interact, so that the perceptual importance of any one dimension depends on values of the others.
Modulation of voice related to tremor and vibrato
Study 2…………………………………………………………………………..76 Method………………………………………………………………………76 Acoustical and perceptual data………………………………………...76 Acoustical analyses……………………………………………………...77 Statistical analyses……………………………………………………...78 Results……………………………………………………………………….79 Glottal noise……………………………………………………………..83 No glottal noise………………………………………………………….83 Discussion…………………………………………………………………...84 Conclusions……………………………………….……………………………..87 CHAPTER 4: ACOUSTICAL BASES FOR THE PERCEPTION OF VIBRATO AS A MODEL OF VOCAL TREMOR……………………………………………………88 Introduction……………………………………………………………………..88 Study 1…………………………………………………………………………..88 Method………………………………………………………………………88 Singers…………………………………………………………………...88 Data collection…………………………………………………………..89 Audio stimuli……………………………………………………………90 Listeners…………………………………………………………………91 Listening task…………………………………………………………...91 Data analysis…………………………………………………………….92 Reliability and Agreement……………………………………………..93 Statistical analyses……………………………………………………...93 Results……………………………………………………………………….93 Discussion…………………………………………………………………...94 Study 2………………………………………………………………………..…95 9 TABLE OF CONTENTS-Continued Method………………………………………………………………………95 Acoustical and perceptual data………………………………………...95 Acoustical analyses……………………………………………………...95 Statistical analyses……………………………………………………...97 Results……………………………………………………………………….97 Female………………………………………………………………….100 Male…………………………………………………………………….100 Discussion………………………………………………………………….101 Conclusions…………………………………………………………………….104 CHAPTER 5: CONCLUSIONS AND FUTURE DIRECTIONS…………………..106 Conclusions…………………………………………………………………….106 Future Directions……………………………………………………………...108
Acoustic Studies of Tremor in Pathological Voices
This work is focused on modeling the perception of tremor found in pathological voices. The main research objective is to automatically separate the different sources of tremor to estimate the magnitude of tremor perturbations using signal processing techniques. A new assessment algorithm is derived from speech recordings which combines non-linear filtering, amplitude demodulation and spectral estimation techniques. The algorithm is evaluated against the perceptual judgments provided by speech pathologists and other reported indexes. The results show that the algorithm is effective differentiating normal from pathological tremor and it is a reliable measurement of tremor perturbations with high correlation with perceptual judgments.
Phonatory characteristics of vocal fold tremor
Journal of Phonetics, 1986
To identify phonatory measures of vocal fold tremor, patients with benign essential tremor (BET) of the vocal folds were compared with normal controls and patients with phonatory tremor due to other neurological disorders. Measures included: the percent frequency and amplitude variation due to tremor, range, rate and regularity of tremor. Patients with neurological disorders (including BET) had greater frequency and amplitude range and percent variation due to tremor, but no increase in jitter and shimmer. The acoustic measures which specifically reflected vocal fold tremor in BET were the range in frequency variation and the variation in linear trend in frequency and amplitude. Tremor rate did not differ between BET, other neurological disorders and normal voices, but the regularity of the tremor rate did.
Journal of the Acoustical Society of America, 2016
The purpose of this study was to investigate the effects of physiological adjustments on listeners' perception of the magnitude of modulation of voice and to determine the characteristics of the acoustical modulations that explained listeners' judgments. This research was carried out using singers producing vibrato as a model of vocal tremor. Twenty healthy adults participated in a perceptual study involving pair-comparisons of the magnitude of "shakiness" with singers' samples, which differed by fundamental frequency, vocal quality, and vowel. Results revealed that listeners perceived a higher magnitude of voice modulation when female samples had a pressed vocal quality. Acoustical analyses were performed with voice samples to determine the features that predicted listeners' judgments. Based on regression analyses, listeners' judgments were predicted to some extent by modulation information in frequency bands across the spectrum.
Phonatory Characteristics of Male Patients with Classic Essential Tremor
Journal of Movement Disorders, 2021
Objective Voice tremor (VT) is one of the characteristics of essential tremor (ET). This study was designed to describe the group and phonatory characteristics of classic ET patients with VT.Methods This retrospective case-control study compared classic ET patients with age and sex-matched controls. The ET population was subgrouped based on auditory perceptual voice analysis. Electroglottography and acoustic voice samples obtained from both groups were analyzed for contact quotient (CQ) and multidimensional voice program parameters, i.e., fundamental frequency (F0), perturbation, noise, and tremor parameters.Results The CQ, F0, perturbation, noise, and tremor characteristics significantly increased from the moderate VT group to the severe VT group.Conclusion The CQ, F0, and noise characteristics reflected the vocal folds’ functionality. The perturbation and tremor parameters variation were reasoned considering the tremor-related changes occurring in the laryngeal, vocal tract, and e...
Discriminating Simulated Vocal Tremor Source Using Amplitude Modulation Spectra
Journal of voice : official journal of the Voice Foundation, 2014
Sources of vocal tremor are difficult to categorize perceptually and acoustically. This article describes a preliminary attempt to discriminate vocal tremor sources through the use of spectral measures of the amplitude envelope. The hypothesis is that different vocal tremor sources are associated with distinct patterns of acoustic amplitude modulations. Statistical categorization methods (discriminant function analysis) were used to discriminate signals from simulated vocal tremor with different sources using only acoustic measures derived from the amplitude envelopes. Simulations of vocal tremor were created by modulating parameters of a vocal fold model corresponding to oscillations of respiratory driving pressure (respiratory tremor), degree of vocal fold adduction (adductory tremor), and fundamental frequency of vocal fold vibration (F0 tremor). The acoustic measures were based on spectral analyses of the amplitude envelope computed across the entire signal and within select fre...
Comparative Evaluation of Several Pitch Process Models in the Detection of Vocal Tremor
IEEE Transactions on Biomedical Engineering, 2000
Three models describing the speech excitation wave (denoted as pitch process) are suggested in order to detect vocal tremor in pathological speech. These models are compared, and the advantages and disadvantages of each of them are discussed. Comparison results for synthesized speech are presented, as well as spectral analysis results for real data of Parkinsonian speech, from which it turns out that the pitch process may serve as a powerful tool for detecting such tremor.