〔Abstract〕 Objective To investigate the association between single and combined exposure to arsenic (As), mercury (Hg), and cadmium (Cd) in urine and hearing loss in adults. Methods A total of 400 adult patients were recruited for the study, comprising 200 participants in the normal hearing group and 200 in the hearing loss group. General demographic information of the study subjects was collected by a self-administered questionnaire, morning urine samples were tested for As, Hg, and Cd concentrations, and hearing status was assessed by Pure Tone Audiometry. A binary logistic regression model was used to explore the association between the concentrations ofthe three metals in urine and hearing loss, and a Bayesian kernel-machine regression (BKMR) model was used to further explore the association between the concentrations of the three metal mixtures and hearing loss. Results After correction for urinary creatinine, As, Hg, and Cd concentrations were higher in the hearing loss group than those in the normal hearing group (P<0.05). Binary logistic regression indicated that concentrations of As, Hg, and Cd were positively associated with hearing loss, and the risk of hearing loss was significantly higher in the second quartile of Cd concentration compared to the first quartile (OR=2.000, 95% CI: 1.009-3.964). BKMR modeling analysis showed that the combined exposure levels of As, Hg, and Cd significantly increased the risk of hearing loss, with Cd being the most important contributor (posterior inclusion probability=0.412), and that there were potential interactions between As and Cd, and Cd and Hg. Conclusion Combined exposure to As, Hg, and Cd in urine is significantly associated with adult hearing loss, with Cd being the primary contributor in the exposure combination. The interactions between As and Cd, as well as Cd and Hg, may have adverse effects on hearing loss.