The impact of vocal tuning in the perceptual auditory judgment of normal and deviated voice qualities

To evaluate the ability that in tune and out of tune individuals have to identify normal and deviated voice qualities and to compare it with their performance in auditory processing tests and perceptual judgment.

The study investigated 15 in tune and 15 out of tune individuals. Participants were matched for age and sex, were amateur choir singers, had normal hearing thresholds and normal vocal quality. All individuals underwent Pitch-matching scanning to be classified as in or out of tune. Next, they performed the Pitch Pattern Sequence (PPS) and the Duration Pattern Sequence (DPS) tests and the perceptual judgment of 36 voices plus 20% of repetition for reliability analysis.

The out of tune individuals had worse performance in the PPS and DPS for both ears (p=0.002 RE; p=0.001 LE; p=0.009 DPS); no difference was observed in the perceptual judgment and the reliability (p=0.153). However, participants with normal PPS and DPS had better performance in the perceptual judgment and better reliability (p=0.033). Thus, individuals with disorders in temporal auditory processing skills have greater difficulty in the perceptual judgment and have lower intra-rater reliability, despite being in or out of tune.

It can be observed that voice tone is not required to guarantee good perceptual judgment. However, temporal patterns and intra-rater reliability are essential to perceptually assess normal and altered voice qualities. Therefore, auditory training should be included in programs that aim to develop voice perceptual judgment abilities.