Acquired Central Auditory Processing Disorder in Service Members and Veterans

Abstract

Purpose A growing body of evidence suggests that military service members and military veterans are at risk for deficits in central auditory processing. Risk factors include exposure to blast, neurotrauma, hazardous noise, and ototoxicants. We overview these risk factors and comorbidities, address implications for clinical assessment and care of central auditory processing deficits in service members and veterans, and specify knowledge gaps that warrant research. Method We reviewed the literature to identify studies of risk factors, assessment, and care of central auditory processing deficits in service members and veterans. We also assessed the current state of the science for knowledge gaps that warrant additional study. This literature review describes key findings relating to military risk factors and clinical considerations for the assessment and care of those exposed. Conclusions Central auditory processing deficits are associated with exposure to known military risk factors. Research is needed to characterize mechanisms, sources of variance, and differential diagnosis in this population. Existing best practices do not explicitly consider confounds faced by military personnel. Assessment and rehabilitation strategies that account for these challenges are needed. Finally, investment is critical to ensure that Veterans Affairs and Department of Defense clinical staff are informed, trained, and equipped to implement effective patient care. Infographic https://doi.org/10.23641/asha.12071232

Blast Exposure and Self-Reported Hearing Difficulty in Service Members and Veterans Who Have Normal Pure-Tone Hearing Sensitivity: The Mediating Role of Posttraumatic Stress Disorder

“…Considering the magnitude of the observed mediation, our results suggest that the association between blast exposure and self-reported hearing difficulty among those with normal pure-tone hearing sensitivity may also be mediated through other pathways. From an audiologic perspective, possible mechanisms include subclinical damage to the cochlea (i.e., undetectable peripheral hearing loss; Kujawa & Liberman, 2009) and central auditory nervous system dysfunction Tepe et al, 2020). Some early evidence exists to support each of these mechanisms, although prospective studies capable of empirically testing such mediation are lacking.…”

“…No one has previously studied the role of PTSD as a possible mediator between blast exposure and hearing sequelae. Relevant studies have only expressed the high co-occurrence of blast exposure and PTSD, noting the marked complexity in understanding the contributions of PTSD to the observed association (Bressler et al, 2017;Gallun et al, 2016;Saunders et al, 2015;Tepe et al, 2020). This points to the need for a unifying conceptual framework for blastrelated functional hearing difficulties that integrates PTSD.…”

Dementia in military and veteran populations: a review of risk factors—traumatic brain injury, post-traumatic stress disorder, deployment, and sleep

“…Acquired central auditory processing disorder (ACAPD) is a disorder associated with military deployment due to multiple possible factors such as blast exposure, TBI, hazardous noise exposure, and ototoxic solvents [ 71 ]. Signs of central auditory dysfunction have also been noted in patients with mild probable AD by Gates et al .…”

Concussion Management Guidelines Neglect Auditory Symptoms

“…27 However, because distinguishing auditory signals such as speech from background noise is a particularly challenging task for the central auditory system, patients may also endorse symptoms of noise sensitivity stemming from poorer auditory functioning in environments with competing noise sources after head injury. 20 Thus, asking the patient to give examples is necessary to distinguish hyperacusis from noise sensitivity and hearing difficulties related to background noise. There are multiple types of decreased sound tolerance conditions, and they are not mutually exclusive.…”