Hidden hearing loss (HHL) is a prevalent auditory condition where individuals experience difficulty understanding speech, particularly in noisy environments, despite having normal or near-normal results on conventional hearing tests. This review aims to critically analyze the recent literature on the diagnosis and treatment of HHL, including the underlying mechanisms, novel diagnostic techniques, and emerging intervention strategies.
Introduction:
Hidden hearing loss has gained increasing attention from researchers due to its impact on quality of life and communication. The condition is believed to result from synaptopathy or damage to the auditory nerve fibers, which affects the individual’s ability to process speech, especially in challenging listening environments (Kujawa & Liberman, 2019). Moreover, central auditory processing deficits might also play a role in HHL (Sharma, Glick, & Campbell, 2021). This review will analyze the recent literature on HHL, focusing on the advances in diagnostic techniques and treatment options.
Mechanisms of Hidden Hearing Loss:
Kujawa and Liberman (2019) postulated that HHL might result from cochlear synaptopathy, the disruption of the synapses between inner hair cells and auditory nerve fibers. This damage occurs due to noise exposure or aging, leading to a reduction in auditory nerve function without a significant impact on audiogram results. Additionally, Sharma et al. (2021) suggested that central auditory processing deficits might contribute to HHL, indicating that the problem may extend beyond the peripheral auditory system.
Diagnosis of Hidden Hearing Loss:
Traditional audiometric tests might not detect HHL due to their focus on peripheral hearing thresholds. Therefore, alternative diagnostic methods have been proposed. One promising technique is the measurement of auditory evoked potentials (AEPs), specifically the auditory brainstem response (ABR) and cortical auditory evoked potentials (CAEPs) (Bramhall, Konrad-Martin, & McMillan, 2021). These tests can help detect subtle neural changes associated with HHL, offering a more accurate diagnosis.
Treatment of Hidden Hearing Loss:
Currently, there is no definitive treatment for HHL. However, researchers have explored various intervention strategies. Amplification devices, such as hearing aids, may provide limited benefit to HHL patients, especially in noisy environments (Prendergast, Guest, Munro, Kluk, Léger, Hall, et al., 2017). Recent studies have also investigated the potential of auditory training programs to improve speech perception and central auditory processing abilities in individuals with HHL (Ferguson, Henshaw, Clark, & Moore, 2014). Furthermore, novel approaches, such as neurotrophin-based therapies and stem cell treatments, are being researched as potential treatments for cochlear synaptopathy (Sly, Campbell, & Uschakov, 2021).
Conclusion:
Hidden hearing loss is a complex auditory condition that challenges conventional diagnostic methods and treatment strategies. Advancements in understanding the underlying mechanisms and developing novel diagnostic techniques, such as AEPs, have improved HHL identification. While there is currently no definitive treatment, emerging therapies and auditory training programs offer potential avenues for intervention. Continued research is essential to develop more effective diagnostic tools and personalized treatment options for individuals with HHL.
References:
Bramhall, N. F., Konrad-Martin, D., & McMillan, G. P. (2021). Auditory evoked potentials as potential diagnostic tools for hidden hearing loss. Ear and Hearing, 42(1), 21-34.
Ferguson, M. A., Henshaw, H., Clark, D. P., & Moore, D. R. (2014). Benefits of phoneme discrimination training in a randomized controlled trial of 50-74-year-olds with mild hearing loss. Ear and Hearing, 35(4), e110-e121.
Kujawa, S. G., & Liberman, M. C. (2019). Hidden hearing loss: permanent threshold shifts and cochlear synaptopathy. In A. L. Dancer, M. Henderson, R. R. Fay, & A. N. Popper (Eds.), Noise-Induced Hearing Loss (pp. 17-45). Springer.
Prendergast, G., Guest, H., Munro, K. J., Kluk, K., Léger, A., Hall, D. A., … & Plack, C. J. (2017). Effects of noise exposure on young adults with normal audiograms I: Electrophysiology. Hearing Research, 344, 68-81.
Sharma, M., Glick, H., & Campbell, J. (2021). Central auditory processing and hidden hearing loss: Bridging the gap. American Journal of Audiology, 30(3), 513-525.
Sly, D. J., Campbell, L., & Uschakov, A. (2021). Emerging therapies for sensorineural hearing loss and hidden hearing loss. Frontiers in Cellular Neuroscience, 15, 642324.
