Review on auditory pitch perception in ASD (Chen et al., 2022)

Purpose: Pitch plays an important role in auditory perception of music and language. This study provides a systematic review with meta-analysis to investigate whether individuals with autism spectrum disorder (ASD) have enhanced pitch processing ability and to identify the potential factors associated with processing differences between ASD and neurotypicals.

Method: We conducted a systematic search through six major electronic databases focusing on the studies that used nonspeech stimuli to provide a qualitative and quantitative assessment across existing studies on pitch perception in autism. We identified potential participant- and methodology-related moderators and conducted metaregression analyses using mixed-effects models.

Results: On the basis of 22 studies with a total of 464 participants with ASD, we obtained a small-to-medium positive effect size (g = 0.26) in support of enhanced pitch perception in ASD. Moreover, the mean age and nonverbal IQ of participants were found to significantly moderate the between-studies heterogeneity.

Conclusions: Our study provides the first meta-analysis on auditory pitch perception in ASD and demonstrates the existence of different developmental trajectories between autistic individuals and neurotypicals. In addition to age, nonverbal ability is found to be a significant contributor to the lower level/local processing bias in ASD. We highlight the need for further investigation of pitch perception in ASD under challenging listening conditions. Future neurophysiological and brain imaging studies with a longitudinal design are also needed to better understand the underlying neural mechanisms of atypical pitch processing in ASD and to help guide auditory-based interventions for improving language and social functioning.

Supplemental Material S1. PRISMA checklist.

Supplemental Material S2. Characteristics of studies included in quantitative synthesis.

Supplemental Material S3. Overall pitch processing performance (accuracy) of ASD participants.

Supplemental Material S4. Results of leave-one-out sensitivity analysis sorted by heterogeneity (I2). The shaded area with a dashed line in its center represents the estimated pooled effect and its 95% confidence interval of included studies.

Supplemental Material S5. Forest plot after removing outliers. Forest plot with effect size (Hedges's g) and confidence intervals for included studies after the removal of three outliers. 

Supplemental Material S6. Contour-enhanced meta-analysis funnel plots. 

Supplemental Material S7. Funnel plot. The effect size for each study (Hedges's g) is plotted against the standard error. 

Supplemental Material S8. Results of the meta-regression analyses.

Chen, Y., Tang, E., Ding, H., & Zhang, Y. (2022). Auditory pitch perception in autism spectrum disorder: A systematic review and meta-analysis. Journal of Speech, Language, and Hearing Research. Advance online publication. https://doi.org/10.1044/2022_JSLHR-22-00254