Does the Accuracy of Medical Diagnoses Affect Novice Listeners' Auditory-Perceptual Judgments of Dysphonia Severity?

OBJECTIVE/HYPOTHESIS: To determine whether the presence and accuracy of a laryngeal medical diagnosis affects novice listeners' judgments of dysphonia.

STUDY DESIGN: Prospective, within subjects, modified factorial experimental design.

METHODS: Twenty-six speakers with dysphonia and four normophonic speakers provided speech recordings. Forty novice clinicians evaluated speech samples for roughness and breathiness using 100-mm visual analog scales in two conditions. First, speech samples were presented without diagnostic information. In the second condition, 50% of the speech samples were presented with the accurate laryngeal medical diagnosis, while the other 50% of samples were presented with an inaccurate (alternative) diagnosis.

RESULTS: Results showed that judgments of dysphonia were affected by the presence of both accurate and inaccurate diagnoses. As expected, when compared to no known diagnosis, judgments of roughness significantly increased in severity when an accurate diagnostic label of vocal fold lesions was presented. Likewise, in comparison to no known diagnosis, judgments of breathiness trended toward an increase in severity when an accurate diagnostic label of vocal fold paralysis/paresis was presented. Interestingly, increases in perceived severity of dysphonia were also observed with the presentation of inaccurate diagnoses, with the overall effect of inaccurate diagnostic information being greater than accurate diagnoses. Specifically, increases in perceived roughness and breathiness were observed when inaccurate diagnoses included benign vocal fold lesion(s) and vocal fold paralysis/paresis. In contrast, inaccurate diagnostic labels indicating "clear larynx" or diagnoses other than benign vocal fold lesion(s) or paralysis/paresis resulted in decreased perceived roughness and breathiness severity. The magnitude of the differences in perceived severity between conditions was overall reduced for breathiness compared to roughness.

CONCLUSIONS: Sources of bias such as knowledge and accuracy of medical diagnoses should be considered when novice clinicians use auditory-perceptual measures to evaluate dysphonia and measure treatment outcomes.