Noise-induced hearing loss (NIHL), a common sensory disorder, is traditionally thought to stem primarily from direct damage to sound-sensing hair cells (HCs). Here, we demonstrate that supporting cells (SCs), neighboring cells not previously implicated in NIHL pathogenesis, orchestrate hearing loss and HC degeneration through Gasdermin D (GSDMD) activation. Mechanistically, noise-induced oxidative stress in HCs triggers activation of epidermal growth factor receptor in SCs, leading to extracellular-regulated kinase phosphorylation and caspase-11-dependent cleavage of GSDMD, thereby establishing an HC-to-SC signaling cascade. Furthermore, GSDMD activation in SCs reciprocally exacerbates oxidative injury in HCs, creating a pathogenic positive feedback loop between the two cell types. Our findings uncover a central role for SCs in noise-induced hearing loss and identify GSDMD-mediated intercellular communication as a potential therapeutic target.