Different voice analysis programs use similar descriptions to define voice perturbation measures. A total of 47 voice samples reflecting a spectrum of normal and pathological voices were randomly selected from a database, and the same voice samples were used to obtain mean fundamental frequency, jitter, shimmer, and noise-to-harmonics ratio results from 2 acoustic analysis programs.
Open in a separate window The pre-operative mean jitter was 3. The mean HNR in males was 3. In females, the pre-operative HNR was 3. Stroboscopic Parameters Pre- and post-operative morphology was studied using stroboscopy for all patients. Only one patient was found to have recurrent lesion after the third follow-up visit, who was diagnosed with recurrent papillomatosis.
Mucosal wave and glottic closure patterns were studied. After surgery, all patients achieved complete glottis closure. However, one patient had recurrent papillomatous lesion in the third month, and therefore had incomplete glottis closure. Mucosal wave pattern was studied to look for amplitude, periodicity and symmetry.
Discussion Voice outcome following microlaryngeal surgery is the major concern for the patient as well as the surgeon. Refinement in micro-surgical techniques as described by Strong, Hirano, Bochayer etc. Since its introduction in laryngeal surgeries, carbon dioxide laser is being increasingly used for surgery of such lesions.
In spite of various studies showing good voice outcome with carbon dioxide laser, in many centres laser is not used due to concerns regarding lateral thermal damage produced by it.
Our study was undertaken to evaluate voice outcome and vocal fold function following carbon dioxide laser excision for benign lesions Compare jitter shimmer and harmonics to vocal fold.
As the most important etiological factor that is implicated is voice abuse or overuse, these lesions are found in the most active age-group and more commonly in males. This observation is supported by the findings of Stewart et al. The most common lesion was vocal polyp, as was observed in other studies by Geyer, Benninger et al.
Perceptual Analysis Various scoring systems are available for perceptual analysis of voice. GRBAS offers an easy scoring system for measuring degree of change of voice. Acoustic Analysis Voice outcome was objectively measured by acoustic analysis.
Jitter and shimmer are measures of level of perturbation of two important parameters voice—pitch and intensity. Objective record of these measures allows comparison between pre- and post-operative values. Both are considered as reliable indicators of vocal fold function [ 58 ].
Several studies have shown F0 range as the measure of treatment efficacy. Our study showed that mean F0 tends to change towards more physiological values for both males and females after the surgery.
Harmonics to noise ratio HNR is a quantitative index of the degree of hoarseness. In our study, comparison of pre- and post-operative HNR showed improvement which was statistically significant.
Similar findings with respect to F0, shimmer, jitter and HNR were observed by Benninger in their randomized prospective study [ 5 ]. Improvement in the acoustic parameters were also observed by Remacle [ 8 ] and more recently by Geyer et al. Acoustic characteristics of voice depend on the mass and tension of vocal folds.
The improvement in the acoustic parameters can be explained on the basis of improved contact between the cord and better vibratory characteristics. Stroboscopic Changes Stroboscopy provides excellent endoscopic picture and helps in evaluating pattern of mucosal fold vibration.
The parameters selected were glottic closure pattern and mucosal wave as these are two important factors that affect quality of voice [ 10 ]. Complete glottic closure can be explained by improved contact between the vocal folds after excision of the lesion.
Acoustic parameters such as fundamental frequency (F0), vocal intensity, perturbation of the frequency (jitter), perturbation of amplitude (shimmer), harmonic-to-noise ratio, and maximum phonation frequency range helps to identify the physiological changes of the laryngeal system. Compare jitter, shimmer and harmonics to noise ratio in terms of the types of information each provides? Jitter and shimmer are measures of the cycle-to-cycle variations of fundamental frequency and amplitude, respectively, which have been largely used for . tic perturbation measures: jitter, shimmer, and harmonics-to-noise ratio (HNR). 4 Jitter and shimmer are typically computed in the time domain and indicate variations in the cycle-to-cycle period.
Mucosal wave also tends to become regular and normal after surgery as the improved contact between vocal folds results in better generation of sub-glottic pressure, hence better amplitude of cord vibration [ 11 ]. Benninger [ 5 ] conducted a randomized prospective trial comparing microspot CO2 laser with micro-dissection in treatment of benign lesions of vocal folds on 37 patients.
Stroboscopic parameters, perceptual and acoustic analysis were performed in both groups. No statistically significant difference existed between the two groups over time.Philadelphia Comparisons of Jitter, Shimmer, and Signal-to-Noise Ratio from Directly Digitized Versus Taped Voice Samples Marylou Pausewang Gelfer and Dawn M.
Fendel Department of Communication Sciences and Disorders, University of Wisconsin-Milwaukee, Wisconsin, U.S.A. Summary: The purpose of this study was to compare .
Jitter and shimmer are measures of the cycle-to-cycle variations of fundamental frequency and amplitude, respectively, which have been largely used for the description of pathological voice.
Analysis of fundamental frequency, jitter, shimmer and vocal intensity in children with phonological disorders Some studies were developed to compare perceptually and acoustically the voice of children with and jitter and shimmer, in children with phonological disorders.
Free Essay: Compare jitter, shimmer and harmonics to noise ratio in terms of the types of information each provides? Jitter and shimmer are measures of the.
Introduction • Jitter, shimmer, and harmonics-to-noise ratios are the cornerstones of acoustic voice measurement. • The role these acoustic attributes play in the. Jitter and Shimmer Measurements for Speaker Recognition Mireia Farrús, Javier Hernando, Pascual Ejarque TALP Research Center, Department of .