From sound waves to molecular and cellular mechanisms: Understanding noise‑induced hearing loss and pioneering preventive approaches (Review)

Abstract

Noise-induced hearing loss (NIHL) is a significant and urgent global public health concern, arising from prolonged exposure to elevated levels of noise. This auditory impairment harms delicate inner ear structures, particularly the essential hair cells transmitting auditory signals to the brain. Recognized by the World Health Organization as a major contributor to worldwide hearing loss, NIHL requires a comprehensive examination of its molecular and cellular mechanisms. Animal models emerge as indispensable tools for unraveling these intricacies, allowing researchers to simulate and study the impact of noise exposure on auditory structures, shedding light on the interplay of oxidative stress, inflammation and immune responses-crucial factors in NIHL progression. The present review focuses on elucidating the molecular mechanisms of NIHL, with a specific emphasis on findings derived from animal models, alongside the exploration of thorough preventive strategies, including protective measures and probing potential interventions. Understanding the molecular underpinnings not only provides insight into targeted treatment approaches, but also unlocks pathways for exploring and implementing preventive actions. This approach not only deepens the current comprehension of NIHL, but also has the potential to influence the shaping of public health policies, offering a nuanced perspective on this prevalent auditory disorder.

Keywords: animal models; cochlea; hair cells; noise-induced hearing loss; preventive measures.

Figure 1

Pathophysiology of noise-induced hearing loss. Prolonged exposure to loud noise triggers inflammation and oxidative stress, initiating inflammatory events in the cochlea. Elevated cochlear calcium and free radicals, induced by noise, further activate immune processes, leading to direct and calcium-mediated vasoconstriction. This process causes cellular damage and activation of cell death pathways, resulting in hearing impairment. The figure was created using BioRender.com.

Figure 2

Contributing factors of NIHL. Noise originating from various sources causes auditory damage and leads to hearing loss. The type, intensity, duration and frequency of noise exposure all play crucial roles in the extent of the damage. Environmental noise from urban areas, recreational activities and community settings, combined with occupational noise from industries, construction, and service sectors, significantly contributes to NIHL. NIHL, noise-induced hearing loss. The figure was created using BioRender.com.