Structural and Functional Brain Alterations Induced by Environmental Noise Exposure: A Comprehensive Review

Environmental noise exposure has become an increasingly prevalent public health con-cern, with effects extending beyond the auditory system. Accumulating evidence indicates that chronic noise exposure induces both structural and functional alterations in the cen-tral nervous system, ultimately affecting cognitive and emotional processes. This review summarizes the impact of noise on key brain regions, including the hippocampus, pre-frontal cortex, and auditory cortex. Structurally, noise exposure is associated with reduced neurogenesis, dendritic remodeling, synaptic loss, alterations in white matter and changes in glial activity. Functionally, it disrupts synaptic plasticity mechanisms—such as long-term potentiation and long-term depression—as well as neuronal connectivity, lead-ing to impairments in higher-order cognitive and behavioral functions. These effects are mediated by interconnected mechanisms, including activation of the hypothalamic–pituitary–adrenal axis, neuroinflammation, oxidative stress, and alterations in neu-rotrophic signaling.