Does the presence or location of graphic markers affect untrained listeners' ratings of severity of dysphonia?

Abstract

Objective: To determine the effect of presence and location of severity labels for different types of visual analog scales (VAS) on overall severity (OS) ratings in dysphonic speech.

Study design: Experimental, between group comparisons.

Methods: Dysphonic and normal voice samples from male and female speakers were presented to inexperienced listeners for judgments of OS. To rate samples, listeners used an undifferentiated 100-mm VAS labeled at the extremes, a VAS with nonlinearly distributed labels as in the "beta" version of the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V), or a VAS with symmetrically distributed labels as in the "official" version of the CAPE-V.

Results: Overall, mean OS ratings did not differ significantly across scale types, although ratings using the nonlinearly marked VAS were generally lower than those from other scales. This effect was significant for female speakers whose samples tended toward moderate OS. The ratings distribution, when compiled into 10-mm bins, differed significantly by scale type, with users of the nonlinearly marked scales skewing their ratings toward normal.

Conclusions: The presence and placement of labels on VAS did not significantly affect OS ratings overall, but values were significantly lower when rating female voices with the nonlinearly labeled VAS. Results indicate that professionals should specify the scale type used for rating OS and use scales consistently when comparing voices.

Keywords: Dysphonia; Perceptual rating; Severity; Visual analog scale.