PP302 - Addressing the Service Gap in Auditory Neuropathy Spectrum Disorder (ANSD) in Adults: A Case Study

Abstract:
This case study highlights a young adult with normal hearing thresholds who struggled with speech-in-noise perception, auditory fatigue, and social difficulties. Despite normal audiograms, comprehensive testing revealed severe auditory processing disorder and signs of Auditory Neuropathy Spectrum Disorder (ANSD). Management included fitting low-gain hearing aids, use of a remote microphone, and communication strategies to address these challenges. The patient’s quality of life and social interactions were significantly impacted, emphasizing the need for individualized, evidence-based care. Ongoing monitoring and potential consideration of cochlear implants underscore the importance of a holistic, interdisciplinary approach to addressing hidden hearing loss in young adults.

Summary:

Introduction: Hearing difficulties in individuals with normal hearing thresholds often go undiagnosed, creating a gap in audiological care. Despite normal audiograms, many report significant trouble understanding speech in noise, particularly those with histories of otitis media, exposure to loud sounds, ADHD, or speech delays. This case study describes a young adult with normal hearing thresholds but persistent issues with speech-in-noise perception, auditory fatigue, and social challenges, highlighting the need for thorough assessments and tailored, interdisciplinary care.

Methods: A 20-year-old female reported increasing difficulty understanding speech in both quiet and noisy environments. Initial tests showed normal hearing thresholds, but speech understanding was only 70-80%, below expectations. This prompted further evaluation using SCAN-3, QuickSIN, Transient Otoacoustic Emissions (TrOAEs), Auditory Brainstem Response (ABR), and Cortical Auditory Evoked Potentials (CAEPs). The Vanderbilt Fatigue Scales (VFS-10) and a detailed case history indicated no otitis media, family hearing loss, or noise exposure. Quality of life was measured using the Meaning of Life Questionnaire.

Results: QuickSIN testing revealed severe bilateral speech-in-noise difficulties, far worse than predicted by the audiogram. SCAN-3 results indicated a profound auditory processing disorder (0.1 percentile) across all subtests, including Filtered Words, Competing Words - Directed Ear, and Competing Sentences. TrOAE findings demonstrated robust outer hair cell function, while ABR testing showed dyssynchrony of the auditory nerve fibers, with absent neural responses and present cochlear microphonics, consistent with ANSD. Abnormal ABR morphology persisted even at lower stimulation rates, underscoring significant neural dyssynchrony. Onset CAEP data confirmed intact sound detection, consistent with normal hearing thresholds; however, sound discrimination CAEP was not assessed. The VFS-10 score revealed moderate auditory and emotional fatigue, with the patient reporting social isolation, particularly in multi-talker environments and during rapid speech. Quality of life was significantly impacted, especially in social interactions.

The patient and his mother expressed relief at finally receiving a diagnosis after searching for an explanation for his difficulties over the past two decades. The management plan began with fitting low-gain hearing aids, following the American Academy of Audiology Pediatric Amplification Guidelines for adolescents with mild-to-moderate hearing loss and ANSD. The hearing aids were programmed with an additional 10 dB HL gain above NAL-NL2 targets from 250-8kHz. A remote microphone was also provided to enhance speech-in-noise perception, along with supplementary support strategies, including visual cues and access to closed captioning via Iowa Access.

Conclusion: This case underscores the need for individualized, evidence-based management of ANSD in young adults. The study is ongoing, with continuous monitoring and adjustments to the treatment plan. While amplification has been implemented, cochlear implantation will be considered if real-life benefits are insufficient. Throughout this process, visual cues, communication strategies, and remote microphones are being utilized to enhance auditory access and support effective communication. These findings highlight the broader impact of “hidden hearing loss” in young adults, emphasizing the importance of a holistic, interdisciplinary approach to address both auditory challenges and the emotional effects of social isolation.