Perceptual speech and voice analysis is an essential skill for all speech-language pathologists, but it is a difficult skill to teach. Even the reliability for experienced experts is variable. Some training literature and practices in speech-language pathology suggest that imitating pathological voices may be useful for developing perceptual judgment. Evidence from other fields suggests that motor experience influences perception. Until now the link between production and perception of voice quality has not been addressed. The purpose of this pilot study is to test the hypothesis that imitating pathological voice samples would improve the perceptual discrimination abilities of naïve, inexperienced listeners.
Three expert listeners rated 25 voice samples using a perceptual voice evaluation scale, the Grade, Instability, Roughness, Breathiness, Asthenia, Strain Scale (GIRBAS) (Dejonckere et al., 1996), and identified anchor samples for the training protocol. These expert ratings were used to develop summary expert ratings that served as a comparison for the naïve listener ratings. Two groups of naïve undergraduate listeners received training in evaluating voice quality and in administering the GIRBAS. They completed a pretest, a training session, a homework session, and a post-test. During each activity, they rated 6 voices and provided a confidence rating for their scores. The experimental group imitated the voice samples during the study, and the control group completed the training without supplemental motor experience.
It was hypothesized that both listener groups would have improved accuracy and confidence levels between the pretest and post-test, with a larger improvement for the experimental group. Data suggested that training improved naïve listener accuracy and confidence levels and that this improvement was maintained for at least seven days after the initial training. Post-test accuracy for both groups was approximately the same. Imitation did not improve the accuracy of ratings, although those subjects had higher confidence levels. The data supported previous research that found that training improved the accuracy of perceptual voice evaluations. However, the hypothesis that imitation could improve perceptual ratings was not supported by this study and bears further investigation due to the small sample size.