Audiological profiling of 198 individuals with auditory neuropathy spectrum disorder

Abstract

Objective: The study aimed at exploring the audiological characteristics and the relationship between speech identification scores with cortical evoked potential measures and hearing aid benefit in individuals with auditory neuropathy spectrum disorder (ANSD). Study design: We initiated a retrospective study of patients who were diagnosed as having ANSD. In 198 patients with ANSD, patient history, risk factors, degree and configuration of hearing loss, speech identification scores in quiet and noise, otoacoustic emissions (OAE), immittance evaluation, auditory brainstem responses (ABR), long latency responses (LLR) and hearing aid benefit were assessed. Results: The results showed that the majority of the patients had bilateral ANSD with a female to male ratio of 1.25:1 with the majority having a rising configuration of hearing loss. OAEs were present in most with absent stapedial reflexes and ABR. The study also showed that individuals with ANSD do obtain benefit from hearing aids and it is related to the presence of LLR. Conclusions: The present study emphasizes the audiological characteristics of a large group with ANSD. Among the management options, hearing aids were found to be useful in only a few of the patients and other rehabilitation options, such as cochlear implants, need to be explored in future studies. Currently, the determining factors for benefit with hearing aid are speech identification scores and cortical auditory evoked potentials.

Audiological findings from an adult with thin cochlear nerves

“…This suggests that even a slight thinning of the auditory nerve can significantly affect speech perception scores and may not be correlated with auditory nerve thickness. The current patient had normal middle ear functioning with absent acoustic reflex, which correlates with clinical findings of a retrocochlear pathology (8,9). The absence of appropriate conduction of sound from an abnormal auditory nerve could have led to the absence of acoustic reflexes.…”

“…The current patient had worse speech recognition scores for the left ear (12%) compared to those for the right ear (28%). In individuals with a poor understanding of speech, low speech recognition scores are more indicative of a retrocochlear pathology than a cochlear pathology (8). The auditory nerve in the left ear was thinner and could have led to poorer speech recognition scores in the left ear compared to that in the right ear.…”

“…ABR can be an indication of a retrocochlear pathology, suggesting the need for further investigation using X-rays. ABR is usually reported to be abnormal in individuals with structural anomalies of the cochlear nerve (3,4) and auditory neuropathy spectrum disorder (8,9). LLR testing assesses the auditory cortex and was performed in the current case.…”

Speech Perception in Quiet and in Noise Condition in Individuals with Auditory Neuropathy Spectrum Disorder

“…They also have poor suprathreshold auditory abilities, particularly those related to auditory temporal processing [1,2] . Behavioral data shows that speech recognition abilities in individuals with ANSD can range from poor recognition ability to fairly good recognition ability [3,4] . In individuals with ANSD, the degree of speech perception deficits appear to be dependent on suprathreshold auditory deficits rather than on audibility [1,2] .…”

Evaluation of Hearing Handicap in Adults with Auditory Neuropathy Spectrum Disorder

“…Thus, administering these two questionnaires would help to determine the degree of handicap experienced by individuals with ANSD. The communication abilities in individuals with ANSD are reported to vary across gender, duration of hearing loss, pure tone thresholds, and unaided speech identification score (SIS) [27,28] . Thus, this study also attempts to determine if demographic details (gender and duration of hearing loss) and audiological test results (audiometric thresholds and SIS) can predict hearing handicap in adults with ANSD.…”