The Laryngoscope · 2008 · 44 citations · 11 references
Language StudiesOtolaryngologySpeech-language PathologyAcousticsPhoneticsPhonologyAcoustic DiagnosticsAcoustic PhoneticsSpeech AcousticsSpeech Sound Disorder Differential DiagnosisVoice DisordersAcoustic AnalysisAdductor Spasmodic DysphoniaDifferential Diagnosis CriteriaDifferential Symptom DiagnosisLikelihood RatiosMuscle Tension DysphoniaPositive Predictive ValuePrecision
Muscle tension dysphonia can mimic adductor spasmodic dysphonia, yet intraword phonatory breaks—considered essential for ADSD—are poorly understood in MTD. The study evaluated whether acoustic analysis of intraword phonatory breaks can objectively differentiate ADSD from MTD, and suggested exploring automation of this analysis. A case‑control acoustic analysis of 41 ADSD and 59 MTD patients measured the presence, frequency, and duration of intraword phonatory breaks. ADSD patients exhibited significantly more phonatory breaks than MTD patients, and diagnostic accuracy varied with break duration, frequency, and sex, indicating that phonatory break analysis shows promise—particularly for men—in distinguishing the two disorders.
Muscle tension dysphonia (MTD) can masquerade as adductor spasmodic dysphonia (ADSD) leading to diagnostic confusion. Intraword phonatory breaks have been offered as the sine qua non of ADSD, however, little is known regarding the presence of phonatory breaks in MTD. This investigation assessed the diagnostic worth of acoustic analysis of phonatory breaks as a possible objective test to distinguish ADSD from MTD.Case-control comparison.Voice samples from patients with confirmed ADSD (n = 41) and MTD (n = 59) were analyzed acoustically to determine the presence, frequency, and duration of phonatory breaks -- defined as complete interruption of phonation within a word. Estimates of sensitivity, specificity, positive and negative predictive value, and likelihood ratios were calculated to determine the precision and worth of phonatory break analysis as a clinical diagnostic test.1) Individuals with ADSD showed a significantly higher number of phonatory breaks as compared with MTD. 2) All measures of diagnostic precision varied according to both duration and frequency of phonatory breaks, with separation of males and females leading to different diagnostic test performance results.The results suggest that phonatory break analysis offers promise as an objective test to distinguish ADSD from MTD, with respectable diagnostic precision, especially among men. Automation of the acoustic analysis procedure should be explored.
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