title: Acoustic measures of symptoms in abductor spasmodic dysphonia.
abstract: Speech of patients with abductor spasmodic dysphonia (ABSD) was analyzed using acoustic analyses to determine: (1) which acoustic measures differed from controls and were independent factors representing patients' voice control difficulties, and (2) whether acoustic measures related to blinded perceptual counts of the symptom frequency in the same patients. Patients' voice onset time for voiceless consonants in speech were significantly longer than the controls (p = 0.015). A principle components analysis identified three factors that accounted for 95% of the variance: the first factor included sentence and word duration, frequency shifts, and aperiodic instances; the second was phonatory breaks; and the third was voice onset time. Significant relationships with perceptual counts of symptoms were found for the measures of acoustic disruptions in sentences and sentence duration. Finally, a multiple regression demonstrated that the acoustic measures related well with the perceptual counts (r2 = 0.84) with word duration most highly related and none of the other measures contributing once the effect of word duration was partialed out. The results indicate that some of the voice motor control deficits, namely aperiodicity, phonatory breaks, and frequency shifts, which occur in patients with ABSD, are similar to those previously found in adductor spasmodic dysphonia. Results also indicate that acoustic measures of intermittent disruptions in speech, voice onset time, and speech duration are closely related to the perception of symptom frequency in the disorder.
authors.affiliation: Department of Communication Disorders, School of Allied Health Professions, Louisiana State University Health Sciences Center, New Orleans 70112-2262, USA. jedgar@lsuhsc.edu
authors.forename: J D
authors.initials: JD
authors.lastname: Edgar
authors.forename: C M
authors.initials: CM
authors.lastname: Sapienza
authors.forename: K
authors.initials: K
authors.lastname: Bidus
authors.forename: C L
authors.initials: CL
authors.lastname: Ludlow
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007821:Laryngeal Muscles / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009128:Muscle Spasticity / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology*; D009465:Neuromuscular Agents / Q000627:therapeutic use; D015588:Observer Variation; D013061:Speech Acoustics; D014832:Voice Disorders / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology*; D014833:Voice Quality
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A