Accuracy of Auditory and Auditory-Visual Voice Quality Perception by Speech Language Pathologists and Ear, Nose, and Throat Specialists

Voice quality is evaluated by speech and language pathologists (SLPs) and ear, nose, and throat (ENT) specialists. They often use either auditory-perceptual assessment or laryngoscopy, which provides visualization of the larynx or both (auditory-visual assessment). This study compared the accuracy of auditory-perceptual voice quality assessment between auditory and auditory-visual assessments, and between SLPs and ENTs. Thirty SLPs and 30 ENTs listened to recordings that represent six voice qualities (high pitch, whisper, strained whisper, vocal fry, strained, and wet voice) realized with the sustained vowel /i/, presented auditorily and auditorily-visually (by laryngoscopy video). They characterized the voice qualities and rated the degree of dominance. The following factors predicted identification accuracy: condition (with/without visual information), voice quality, profession, and the interactions between condition and profession, and between voice quality and profession. SLPs identified whispers, strained whispers, and vocal fries more reliably than ENTs in both conditions. ENTs but not SLPs recognized auditory-visual presentations less accurately than auditory ones. This may be due to different emphases during voice evaluation: SLPs perform a primarily functional voice evaluation that requires sensitivity to various voice qualities, while evaluation by ENTs is mainly anatomical, focusing on laryngeal visualization. The results suggest that visual information from the larynx can impair the accuracy of voice quality perception.