Three Case Studies in the Assessment and Treatment of Auditory Processing Disorder in Adults

Abstract

Background: Some experience significant listening difficulties despite normal audiograms, including those with auditory processing disorder (APD) with or without identifiable comorbidities. This study describes three adults with APD: two with neurodiverse comorbidities and one with APD in the absence of identifiable comorbidity or known etiology. Purpose: We aimed to conduct an in-depth analysis of complex APD presentations and evaluate whether auditory training and/or hearing aids improve listening abilities, using standardized clinical assessments and ecologically valid speech-in-noise measures. Research Design: This was a case study. Study Sample: The study included three adults with APD, all reporting substantial speech-in-noise difficulties despite normal audiometric thresholds. Presentations included attention-deficit/hyperactivity disorder and suspected autoimmune complications following Covid-19 vaccination. Intervention: Participants completed an 8-week phoneme-based spatial-cue training program (Soundiverse), followed by an 8-week hearing aid trial. The training comprised 40 smartphone-based sessions, each comprising two 10-minute games. Data Collection and Analysis: Comprehensive audiological evaluations and an APD diagnostic battery were completed, with selected behavioral tests and questionnaires repeated pre- and postintervention. Sentence-level speech-in-noise tasks assessed generalization to simulated real-world environments. Hearing-aid benefit was evaluated in aided and unaided conditions after the trial. Results: All individuals showed improvements with auditory training and hearing aids, regardless of baseline performance. Phoneme identification improved after auditory training. Sentence-based speech reception thresholds in noise improved after auditory training when measured unaided (pre–post training) and further improved when hearing aids were worn (aided vs. unaided), suggesting that the phoneme-based spatial cue training may extend beyond the phoneme-based discrimination task to enhance sentence-understanding in noise. Self-reported outcomes were more variable and may have continued to reflect not only psychological influences, but also auditory contributors not captured by the re-evaluation battery. Conclusions: Auditory training and hearing aids both enhanced listening abilities in adults with APD, irrespective of the underlying etiology or neurodiverse comorbidity. These findings support noninvasive interventions as effective strategies for enhancing listening ability in individuals with APD presentations. Clinical Relevance Statement: These case studies show that adults with normal audiograms, but persistent speech-in-noise difficulties, may benefit from both auditory training and amplification, providing preliminary guidance for the clinical management of complex APD cases and informing future assessment and intervention frameworks.