Phonatory Characteristics of Male Patients with Classic Essential Tremor (original) (raw)
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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.
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.
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.
Isolated Voice Tremor: A Clinical Variant of Essential Tremor or a Distinct Clinical Phenotype?
Tremor and Other Hyperkinetic Movements, 2020
Background: The consensus statement by the Task Force on Tremor of the International Parkinson and Movement Disorder Society excludes individuals with "isolated voice tremor" as a clinical variant of essential tremor (ET). This clinical viewpoint presents a rationale for reconsideration of "isolated voice tremor" as a clinical variant of ET. Methods: Evidence from the literature was extracted to characterize the clinical phenotype of "isolated voice tremor," or essential vocal tremor (EVT). Clinical features were extracted from relevant literature available at pubmed.gov using the terms "EVT," "essential voice tremor," "primary voice tremor," and "organic voice tremor." Results: The average age of onset in those with EVT was older than 60 years (range 19-84 years), with 75-93% being female. The typical duration of vocal tremor ranged from 1 to 13 years (average 6 years). The distribution of structures exhibiting tremor included the larynx, soft palate, pharynx, and base of tongue in the majority of patients, with some exhibiting tremor of the head and respiratory musculature. The condition of tremor occurred during speech and quiet respiration in 74% of individuals. Rate of tremor ranged from 4 to 10 Hz. Nearly 70% reported onset of vocal tremor prior to upper limb involvement. Family history of tremor was reported in 38-42% of individuals. Discussion: Those previously classified with EVT demonstrate a similar familial history, rate, tremor classification, and body distribution of ET. EVT is proposed as a clinical variant of ET in the pattern of onset and progression of body distribution from the midline cranial to spinal neural pathways.
Effects of simulated source of tremor on acoustic and airflow voice measures
Journal of Voice, 2000
To test the effects of different sources of tremor on the voice, tremor was simulated by external rhythmic perturbation of structures at the subglottal, glottal, and supraglottal levels in 10 healthy subjects. The acoustic and airflow signals simultaneously recorded during sustained phonation in the normal and the 3 simulated tremor conditions were analyzed and compared. Voice measures included: fundamental frequency, 2 short-term perturbation measures (jitter and shimmer), and 3 long-term tremor measures (prominence ratios of the spectral peaks of the acoustic frequency contour, acoustic amplitude contour, and airflow contour). Measures of fundamental frequency and percent shimmer were not significantly affected by the simulated tremors. Measures of percent jitter and the amplitudes of the long-term frequency and amplitude modulations were most prominently increased when respiratory drive was perturbed by simulated tremor. Spectral analysis of the acoustic amplitude contour was most useful in distinguishing the 3 sites of simulated 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
Audio-vestibular evaluation in patients with essential tremor
European Archives of Oto-Rhino-Laryngology, 2011
The aim of this study was to investigate audiovestibular function in patients with essential tremor. Twentythree patients with essential tremor (46 ears) and 21 health control subjects (42 ears) were included in the present study. Patients and comparison subjects were matched for age and gender. All patient and control subjects underwent pure tone audiometric test, tympanogram, transient-evoked otoacoustic emissions and auditory brainstem response. Vestibular system was evaluated by bitermal caloric test. Comparison of variables between the groups was performed. Investigation of the relationship between parameters about ET disease and hearing levels were also studied. Pure tone thresholds significantly differed between patients and controls in 250 and 500 Hz frequencies (p \ 0.05). There was no statistically significant difference in 1,000, 2,000, 4,000, and 6,000 Hz frequencies in essential tremor patients in comparison to the control subjects. A correlation between tremor severity and audiometric scores in low frequencies was not found. In addition, statistical analysis did not demonstrate a correlation between audiometric scores and tremor duration. The otoacoustic emission responses were found significantly different in patient and control group. The latencies of waves I, V and I-V inter-peak latencies on the ABR were not different between the groups. Our findings indicated that, abnormalities are due to cochlea rather than the retro cochlear pathology which is responsible for hearing loss associated with essential tremor.
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.
Reported Hearing Impairment in Essential Tremor: A Population-Based Case-Control Study
Neuroepidemiology, 2007
In a population-based sample, we determined whether a larger proportion of essential tremor (ET) cases reported hearing impairment compared with controls. Ninety-six (38.7%) of 248 ET cases versus 1,371 (29.4%) of 4,669 controls (p = 0.002) reported hearing impairment. In a logistic regression analysis adjusted for age, gender, educational level, depressive symptoms, and dementia, participants who reported hearing impairment were 30% more likely to suffer from ET than were controls (odds ratio 1.3; 95% confidence interval 1.01–1.7; p = 0.04). ET seemed to be associated with reported hearing impairment. The basis for this finding, which has been noted in several studies, deserves further exploration.