Large-scale music events can cause subclinical hearing damage

The WHO warns that over 1.1 billion young people are at risk of hearing loss due to unsafe listening practices, particularly in recreational settings. While traditional studies have focused on changes in hearing sensitivity, typically assessed through standard audiometry, emerging research reveals that noise exposure can also damage cochlear synapses without affecting outer hair cells (OHCs). This "hidden" damage, known as cochlear synaptopathy (CS), impairs the reliable processing of audible sound in complex listening environments while having little or no effect on the traditional measure of hearing sensitivity such as the audiogram. This study offers a unique longitudinal investigation of the relationship between recreational noise exposure and both audiometric and hidden hearing changes, combining personal dosimetry with standard audiometry and physiological markers including otoacoustic emissions and auditory-evoked potentials (AEPs). Forty-two young adults were monitored before and after large-scale music events, with average sound exposure reaching 100 ± 4 dBA over 10.3 ± 4.8 h. Only one participant showed a clinically significant decline in hearing sensitivity, yet five showed acute reductions in AEP markers of synaptic damage within 24 h post-exposure. Two of these cases persisted for 14 days, despite normal audiometric thresholds. No correlation was found between exposure levels and damage, suggesting that individual susceptibility is important. These findings emphasize the limitations of standard hearing sensitivity measures and highlight the need for early diagnostic tests that can detect subclinical, or hidden damage. They call for protective strategies and revised monitoring practices that account for real-life variability in personal exposure and auditory vulnerability.