The Role of Thyroid Hormone Signaling in the Development and Pathophysiology of Hearing: From Molecular Mechanisms to Clinical Applications

Hearing loss (HL) is the most common sensory disorder, affecting over 430 million individuals, and its prevalence continues to rise steadily. Thyroid hormone (TH) signaling is a key endocrine regulator that critically governs key processes in cochlear development, such as sensory hair cell differentiation, ion channel expression, and synaptic maturation. TH deficiency can lead to different types of hearing loss, with or without cochlear structural deformity. Moreover, TH deficiency in pregnant women can cause hearing impairment in newborns. This review synthesizes the mechanisms by which TH signaling contributes to cochlear development and pathogenesis of hearing loss. By integrating insights from human studies and animal models, we discuss the prognostic significance and clinical applicability of TH signaling levels, highlighting the indispensable role of TH signaling in advancing personalized strategies for the diagnosis and management of HL.