Ewa Niebudek-Bogusz

The prevalence and risk factors for occupational voice disorders in teachers.

Objective: Occupational voice disorders in Poland account for over 25% of all occupational diseases. The aim of the study was to assess the prevalence of voice problems in the general population of Polish teachers, and identify risk factors for developing voice pathology. Patients and Methods: The study group comprised 425 female full-time teachers (most of them primary and secondary school, age ranging from 23 to 61 years) and 83 non-teacher women (control) whose jobs did not involve vocal effort, matched for age to the study group. All participants were subjected to a survey using an extensive questionnaire, and to laryngological, phoniatric and videostroboscopic examinations. Results: The overall lifetime vocal symptoms were more frequent in the teachers than in the non-teachers (69 vs. 36%), and in particular it related to permanent and recurrent hoarseness, and dryness in the throat. Mean number of the voice symptoms was 3.21 in teachers and 1.98 in controls (p < 0.001). Abnormal (non-euphonic) voice, neck muscle hypertension during phonation and incorrect resonator function were also significantly more frequent in the teachers. Mean maximum phonation time was shorter in teachers than in the controls (14.3 vs. 15.9 s, p < 0.01). Occupational voice disorders and hyperfunctional dysphonia (that is thought to predispose to such pathology) were found in 32.7% of teachers and 9.6% of control subjects. The probability of developing incomplete glottal closure (odds ratio 13.2x; 95% CI: 1.8–96.8) and hyperfunctional dysphonia (odds ratio 2.7; 95% CI: 1.14–6.44) were significantly higher in the teacher group versus non-teachers. A significant positive relationship was found in teachers between the prevalence of hyperfunctional dysphonia and strained phonation, neck muscle hypertension, instability of voice, self-assessed hyperarousal, and lifetime vocal effort index (years of employment as a teacher × hours of professional activity/week). The prevalence of vocal nodules and incomplete glottal closure were correlated with incorrect phonation technique parameters, but not with psychological factors. No correlation was found with environmental variables, such as classroom temperature, humidity, airborne dust. Conclusion: The prevalence of self-reported symptoms and clinical signs of voice disorders is around 2–3 times more frequent in Polish female teachers than in non-teachers. Lifetime vocal effort, incorrect technique of phonation and psychological predisposition seem to constitute major risk factors for developing occupational voice disorders.

The effectiveness of voice therapy for teachers with dysphonia.

Objective: An incorrect voice emission is a risk factor for developing occupational voice disorders. The study aimed at assessing the effectiveness of voice therapy in female teachers with dysphonia. Methods: The study comprised 133 subjects with voice disorders, taking part in a vocal training programme. A reference group for the present study included 53 teachers with dysphonia. Questionnaire surveys, phoniatric examination and videostroboscopic evaluation were conducted at initial and control examination. Results: In the study group, an improvement after the vocal training was noted in most of the reported symptoms and also in some quantitative parameters of phoniatric examinations compared to the findings for the reference group. The number of patients who assessed their voice as normal increased significantly after the vocal training (2.3 vs. 46.6%). A significant increase in the mean maximum phonation time, from 13.3 to 16.6 s, was observed. The same applied to voice frequency range (increase from 171 to 226.8 Hz). Conclusions: The outcomes of vocal training, such as a subjective improvement of voice quality and an increase in the quantitative parameters (prolonged maximum phonation time, extended voice range) seem to be important parameters for monitoring the effectiveness of training in correct voice emission.

Assessment of the voice handicap index as a screening tool in dysphonic patients.

Objective: The aim of the study was to assess the applicability of the Voice Handicap Index (VHI) in the screening diagnostics of voice dysfunction and in the evaluation of the level of handicap due to dysphonia. Patients andMethods: A total of 165 patients with voice disorders (vocal paresis, benign vocal fold masses, and functional dysphonia) and 65 healthy controls completed the VHI questionnaire. All the participants were subjected to maximum phonation time (MPT) assessment, the patients also to laryngovideostroboscopy. Results: The VHI scores for the patients and controls differed significantly (p < 0.001). A significant correlation (p < 0.05) was found when MPT and VHI were compared. The cutoff point, at which VHI sensitivity (for distinguishing between subjects with voice dysfunction and with vocal health) reached its maximal value (98%) at the highest level of specificity (95%), was assumed to be 12. Conclusions: The study revealed that the VHI is a reliable tool for identifying patients who experience vocal dysfunction and should be used in multidimensional diagnostics of voice disorders. The level of 12 points in the VHI test should be considered to be a threshold for rating the biopsychosocial impact of dysphonia.

Correlation between Acoustic Parameters and Voice Handicap Index in Dysphonic Teachers

Objective: The aim of this study was to investigate the relationship between acoustic analysis and biopsychosocial implications of voice problems, evaluated by the Voice Handicap Index (VHI). Materials and Methods: The study comprised 120 female teachers with voice disorders, evaluated by videolaryngostroboscopy. 60.8% of this group were diagnosed as having functional dysphonia and 39.2% had dysphonia with benign vocal fold masses (nodules and polyps). The controls consisted of 30 euphonic women. The correlations between VHI and acoustic analysis were assessed in both groups using the Pearson correlation coefficient and regression analysis. Results: In teachers, the total VHI score was over 5 times as high as in controls (p < 0.001). Moreover, in teachers, significant positive correlations were found between the total VHI score and the frequency perturbation parameters and amplitude perturbation parameters when both statistical methods were used. These acoustic parameters also significantly correlated with the score on the functional and emotional subscales, but rarely with the physical subscale of the VHI. Conclusions: The study revealed a significant relationship between the objective voice measurements and the VHI. The results confirmed that VHI can be a valuable tool for assessing biopsychosocial implications of occupational dysphonia and should be incorporated in multidimensional voice evaluation.

Acoustic analysis with vocal loading test in occupational voice disorders: outcomes before and after voice therapy.

OBJECTIVE To assess the usefulness of acoustic analysis with vocal loading test for evaluating the treatment outcomes in occupational voice disorders. METHODS Fifty-one female teachers with dysphonia were examined (Voice Handicap Index--VHI, laryngovideostroboscopy and acoustic analysis with vocal loading) before and after treatment. The outcomes of teachers receiving vocal training (group I) were referred to outcomes of group II receiving only voice hygiene instructions. RESULTS The results of subjective assessment (VHI score) and objective evaluation (acoustic analysis) improved more significantly in group I than in group II. The post-treatment examination revealed a decreased percentage of subjects with deteriorated jitter parameters after vocal loading, particularly in group I. CONCLUSIONS Acoustic analysis with vocal loading test can be a helpful tool in the diagnosis and evaluation of treatment efficacy in occupational dysphonia.

Diagnostic value of voice acoustic analysis in assessment of occupational voice pathologies in teachers

It has been shown that teachers are at risk of developing occupational dysphonia, which accounts for over 25% of all occupational diseases diagnosed in Poland. The most frequently used method of diagnosing voice diseases is videostroboscopy. However, to facilitate objective evaluation of voice efficiency as well as medical certification of occupational voice disorders, it is crucial to implement quantitative methods of voice assessment, particularly voice acoustic analysis. The aim of the study was to assess the results of acoustic analysis in 66 female teachers (aged 40–64 years), including 35 subjects with occupational voice pathologies (e.g., vocal nodules) and 31 subjects with functional dysphonia. The acoustic analysis was performed using the IRIS software, before and after a 30-minute vocal loading test. All participants were subjected also to laryngological and videostroboscopic examinations. After the vocal effort, the acoustic parameters displayed statistically significant abnormalities, mostly lowered fundamental frequency (Fo) and incorrect values of shimmer and noise to harmonic ratio. To conclude, quantitative voice acoustic analysis using the IRIS software seems to be an effective complement to voice examinations, which is particularly helpful in diagnosing occupational dysphonia.

Temporal processing disorder associated with styrene exposure.

Little evidence exists on the possible adverse effects of styrene on the central part of the auditory system. The present investigation aimed to study the possible association between styrene exposure and temporal processing abilities. Fifty-nine styrene-exposed subjects and 50 nonexposed control subjects were tested. Pure-tone audiometry (125–8000 Hz) and 3 temporal processing tests (gaps-in-noise, frequency pattern test and duration pattern test) were carried out. Significant differences between groups were found for most of the audiometric thresholds for both ears. ANCOVA analysis showed that styrene-exposed subjects had significantly poorer performances on the frequency and duration pattern tests than nonexposed subjects, when including hearing level and age as covariates. The results of the present research study suggest an association between styrene exposure and central auditory dysfunction characterized by a temporal processing disorder.

Assessment of the influence of osteopathic myofascial techniques on normalization of the vocal tract functions in patients with occupational dysphonia.

ObjectivesOccupational voice disorders are accompanied by increased tension of the external laryngeal muscle which changes the position of the larynx and consequently disturbs the conditions of functioning of the vocal tract. The aim of the study is to assess the use of osteopathic procedures in the diagnosis and treatment of occupational dysphonia.Material and MethodsStudy subjects included 40 teachers with chronic diseases of the voice organ (38 women and 2 men) aged from 39 to 59 (mean age: 48.25). Before and after the voice therapy the osteopathic examination according to Libermann’s protocol was performed as well as phoniatric examination including laryngovideostroboscopy (LVSS), assessment of the maximum phonation time (MPT) and the Voice Handicap Index (VHI) score. The voice therapy, scheduled and supervised by a laryngologist-phoniatrician and conducted by a speech-language pathologist, was supplemented with osteopathic myofascial rehabilitation of the larynx. The chi-square McNemar test and non-parametric Wilcoxon matched pairs test were applied in the statistical assessment.ResultsThe applied interdisciplinary treatment including osteopathic and vocal therapy resulted in a statistically significant decrease in tenderness of muscles raising the larynx (cricothyroid ligament, sternocleidomastoid muscles, and pharyngeal constrictor muscles) and in lowering the tonus (geniohyoid muscles, pharyngeal constrictor muscles and sternocleidomastoid muscles). A significant improvement was also observed in the case of dysfunction of the cricothyroid joint examined during glissando and yawning, as well as in asymmetry of the thyrohyoid apparatus. Moreover, the therapy resulted in significantly better normalization of the head position and better control of the centre of gravity of the body. Statistically significant post-therapy improvement was observed in the phoniatric examination, including VHI scores, MPT results and parameters of videostroboscopic examination.ConclusionsThe use of osteopathic therapy helps significantly improve the functions of the vocal tract in patients with occupational dysphonia.

Applicability of the Polish Vocal Tract Discomfort (VTD) scale in the diagnostics of occupational dysphonia

Abstract Occupational dysphonia is mainly of hyperfunctional origin, expressed by complaints experienced in the vocal tract. The aim of the paper was to evaluate the applicability of the Polish Vocal Tract Discomfort (VTD) scale in the diagnostics of occupational dysphonia. Patients with occupational dysphonia (n = 218) and controls (n = 140) were subjected to the VTD scale, VHI evaluation, and maximum phonation time (MPT) measurement. The patients also underwent videostroboscopy. The comparison of the frequency and severity of VTD symptoms showed that the results of the study group were significantly higher (P = 0.000). The VTD scale is characterized by high values of Cronbachs alpha. This study results indicatethat the VTD scale can be a valuable tool, useful in the diagnostics of occupational dysphonia.

Quantitative assessment of videolaryngostroboscopic images in patients with glottic pathologies

Abstract Introduction: Digital imaging techniques enable exploration of novel visualization modalities of the vocal folds during phonation and definition of parameters, facilitating more precise diagnosis of voice disorders. Aim: Application of computer vision algorithms for analysis of videolaryngostroboscopic (VLS) images aimed at qualitative and quantitative description of phonatory vibrations. Materials and methods: VLS examinations were conducted for 45 females, including 15 subjects with vocal nodules, 15 subjects with glottal incompetence, and 15 normophonic females. The recorded VLS images were preprocessed, the glottis area was segmented out, and the glottal cycles were identified. The glottovibrograms were built, and then the glottal area waveforms (GAW) were quantitatively described by computing the following parameters: open quotient (OQ), closing quotient (CQ), speed quotient (SQ), minimal relative glottal area (MRGA), and a new parameter termed closure difference index (CDI). Results: Profiles of the glottal widths assessed along the glottal length differentiated the study groups (P < 0.001). Moreover, it was shown that the OQ, CQ, CDI, and MRGA indices can be considered as viable parameters for quantifying kinematics of the vocal folds for normophonic subjects and patients with diagnosed vocal nodules and glottal incompetence (P < 0.001). Conclusions: Computer image processing and analysis methods applied to videolaryngostroboscopic images allow for their quantitative assessment. Computation of the size-related and time-related parameters characterizing glottic pathologies is of interest for evidence-based voice diagnostics. Results of the performed ROC curve analysis suggest that the evaluated parameters can distinguish patients with voice disorders from normophonic subjects.