Evaluation of voice acoustic parameters related to the vocal-loading test in professionally active teachers with dysphonia.
BACKGROUND
Teachers are at risk of developing voice disorders. A clinical battery of vocal function tests should include non-invasive and accurate measurements. The quantitative methods (e.g., voice acoustic analysis) make it possible to objectively evaluate voice efficiency and outcomes of dysphonia treatment.


METHODS
To identify possible signs of vocal fatigue, acoustic waveform perturbations during sustained phonation were measured before and after the vocal-loading test in 51 professionally active female teachers with functional voice disorders, using IRIS software. All the participants were also subjected to laryngological/phoniatric examination involving videostroboscopy combined with self-estimation by voice handicap index (VHI)-based scale.


RESULTS
The phoniatric examination revealed glottal insufficiency with bowed vocal folds in 35.2%, soft vocal nodules in 31.4%, and hyperfunctional dysphonia with a tendency towards vestibular phonation in 19.6% of the patients. In the VHI scale, 66% of the female teachers estimated their own voice problems as moderate disability. An acoustic analysis performed after the vocal-loading test showed an increased rate of abnormal frequency perturbation parameters (pitch perturbation quotient (Jitter), relative average perturbation (RAP), and pitch period perturbation quotient (PPQ)) compared to the pre-test outcomes. The same was true of pitch-intensity contour of vowel /a:/, an indication of voice instability during sustained phonation.


CONCLUSIONS
The recorded impairments of voice acoustic parameters related to vocal loading provide further evidence of dysphonia. The voice acoustic analysis performed before and after the vocal-loading test can significantly contribute to objective voice examinations useful in diagnosis of dysphonia among teachers.
Niebudek-Bogusz
Ewa
E
Clinic of Audiology and Phoniatrics, Nofer Institute of Occupational Medicine, św. Teresy 8, 91-348 Łódź, Poland. ebogusz@imp.lodz.pl
Kotyło
Piotr
P
Sliwińska-Kowalska
Mariola
M
D000328:Adult; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D005178:Faculty; D005260:Female; D006801:Humans; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis / Q000503:physiopathology*; D010699:Phonation; D013061:Speech Acoustics; D049489:Stroboscopy; D014832:Voice Disorders / Q000175:diagnosis / Q000503:physiopathology*; D014833:Voice Quality