Auditory Processing and Reading Disability: A Systematic Review and Meta-Analysis

Abstract

Purpose: Reading disability (RD) is frequently associated with deficits in auditory processing (i.e., processing speech and non-linguistic sounds). Several hypotheses exist regarding the link between RD and auditory processing, but none fully account for the range/variety of auditory impairments reported in the literature. These impairments have been primarily summarized by qualitative reviews and meta-analytic evidence for most auditory processing impairments is lacking. Method: We conducted a PRISMA-compliant meta-analysis quantifying the degree to which individuals with RD are impaired on four categories of auditory processing abilities: frequency discrimination, intensity discrimination, duration discrimination, and gap detection. This methodology was accepted and executed as a Registered Report. Results: Auditory processing impairments of medium to large effect size were present in RD vs. typical groups for all categories: frequency (g = 0.79), duration (g = 0.80), and intensity discrimination (g = 0.60), as well as gap detection (g = 0.80). No differences were found across task designs (i.e., testing methods). Conclusion: This meta-analysis documents a large, multiple-domain non-linguistic, auditory processing impairment in RD. Contrary to previous studies, we found a significant deficit in intensity discrimination. The impairments described here must be accounted for by future causal hypotheses in RD and suggest that auditory processing impairments are broader than previously thought.