Effectiveness of the Computed Analysis of Electroglottographic Signals in Muscle Tension Dysphonia

Abstract

Objective: To investigate the usefulness of electroglottography (EGG) parameters in the diagnosis and estimation of efficacy of voice therapy for muscle tension dysphonia (MTD). Patients and Methods: Nineteen MTD participants, an equivalent number of dysphonic (‘organic’) patients with vocal fold lesions and as many normal speakers were enrolled. Acoustic (Ac) and EGG signals during sustained phonation were recorded simultaneously. The period and amplitude perturbation quotient of both signals, the closed quotient (CQ) of EGG signals (mean CQ) and its standard deviation (CQSD) were calculated, and subsequently compared among the three groups. These parameters in the MTD group were compared before and after voice therapy. Results: The perturbation measures of both signals in the MTD group were either as high as or significantly higher than those in the organic group or the control group, respectively. Both the Ac and EGG parameters after therapy significantly decreased. The CQSD, but not mean CQ, also decreased after therapy. Conclusion: EGG parameters related to the regularity of vocal fold vibration, but not to the degree of vocal fold contact (mean CQ), are useful for the diagnosis and estimation of voice therapy outcome in MTD.

Immediate Effects of Humming on Computed Electroglottographic Parameters in Patients With Muscle Tension Dysphonia

“…6, 2014 patients. 5 However, in this previous study, because we did not compare therapeutic and nontherapeutic groups, the therapeutic effects may have been a consequence of vocal hygiene or a natural (spontaneous) cure. Accordingly, in the present study, we investigated the immediate effects of humming on the EGG perturbation parameters to confirm the cause-result relationship between the performance of humming and decreased EGG parameters.…”

“…We previously reported that MTD patients exhibit improved perceptual vocal quality and a reduced degree of supraglottic compression as well as decreased perturbation parameters of both acoustic (Ac) and electroglottographic (EGG) signals and the standard deviation of the contact quotient (CQ) following voice therapy primarily using humming. 4,5 However, because we did not compare therapeutic and nontherapeutic groups, it remains to be confirmed whether these post-therapeutic changes are actually conferred by the humming itself.…”

“…In our previous study, no significant differences were found in CQ values between the parameters obtained before and 2 months after voice therapy including humming. 5 Accordingly, it is assumed that the increase in CQ values observed while performing humming and um-hum phonation is possibly not carried over after performing these tasks. In addition, in the present study, we enrolled untrained MTD and control participants, not singers or actors.…”

“…13 Previous studies have investigated the EGG perturbation parameters in dysphonic patients to estimate irregularities in the vocal fold vibrations. 5,[14][15][16] In addition, we have recently reported that the EGG perturbation parameters showed superior reliability to the Ac parameters in the assessment of MTD patients, as determined using a receiver operating characteristic analysis. 17 Concerning the effects of humming on the condition of the vocal folds, a number of studies have investigated the immediate effects of various vocal training techniques on the degree of glottal adduction using EGG.…”

Influence of F0 and Sequence Length of Audio and Electroglottographic Signals on Perturbation Measures for Voice Assessment

“…20 Regarding voice therapy, EGG may as well be a very sensitive indicator of therapy progress. 21 Although literature shows the importance of EGG in voice evaluation, it lacks information about reliability of perturbation measurements derived from an EGG signal.…”