Automated acoustic analysis of task dependency in adductor spasmodic dysphonia versus muscle tension dysphonia.
OBJECTIVE
Distinguishing muscle tension dysphonia (MTD) from adductor spasmodic dysphonia (ADSD) can be difficult. Unlike MTD, ADSD is described as "task-dependent," implying that dysphonia severity varies depending upon the demands of the vocal task, with connected speech thought to be more symptomatic than sustained vowels. This study used an acoustic index of dysphonia severity (i.e., the Cepstral Spectral Index of Dysphonia [CSID]) to: 1) assess the value of "task dependency" to distinguish ADSD from MTD, and to 2) examine associations between the CSID and listener ratings.


METHODS
Case-Control Study.


METHODS
CSID estimates of dysphonia severity for connected speech and sustained vowels of patients with ADSD (n = 36) and MTD (n = 45) were compared. The diagnostic precision of task dependency (as evidenced by differences in CSID-estimated dysphonia severity between connected speech and sustained vowels) was examined.


RESULTS
In ADSD, CSID-estimated severity for connected speech (M = 39. 2, SD = 22.0) was significantly worse than for sustained vowels (M = 29.3, SD = 21.9), [P = .020]. Whereas in MTD, no significant difference in CSID-estimated severity was observed between connected speech (M = 55.1, SD = 23.8) and sustained vowels (M = 50.0, SD = 27.4), [P = .177]. CSID evidence of task dependency correctly identified 66.7% of ADSD cases (sensitivity) and 64.4% of MTD cases (specificity). CSID and listener ratings were significantly correlated.


CONCLUSIONS
Task dependency in ADSD, as revealed by differences in acoustically-derived estimates of dysphonia severity between connected speech and sustained vowel production, is a potentially valuable diagnostic marker.
Department of Communication Sciences and Disorders, The University of Utah, Salt Lake City, Utah, U.S.A.
Nelson
N
Roy
Alqhazo
A
Mazin
Shaheen N
SN
Awan
D000162:Acoustics; D000293:Adolescent; D000328:Adult; D000368:Aged; D001331:Automation; D016022:Case-Control Studies; D055154:Dysphonia / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007821:Laryngeal Muscles / Q000503:physiopathology*; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D009129:Muscle Tonus / Q000502:physiology*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013035:Spasm / Q000503:physiopathology*; D013068:Speech Production Measurement / Q000379:methods*; D013647:Task Performance and Analysis; D014833:Voice Quality; D055815:Young Adult
ADSD; CSID; MTD; Task dependency