OBJECTIVE: To test the hypothesis that patients with poorly controlled type 2 diabetes mellitus are more likely to develop sensorineural hearing loss (SNHL) than non-diabetic patients. STUDY DESIGN: Retrospective cohort study. SETTING: TriNetX US Collaborative Network (2003-2022). METHODS: Electronic medical record data from the TriNetX US Collaborative Network was queried for subjects without prior hearing loss, defined using medical billing codes (ICD-10, CPT, etc.), who were diagnosed with type 2 diabetes mellitus after January 2003. Patients were stratified by most recent HbA1c (8.0-13.9% or ≥14.0%) and by age at diagnosis (21-30, 31-40, 41-50, 51-60, 61-70, ≥71 years). Primary outcome was development of SNHL ≤20 years after diabetes diagnosis. Cohorts were propensity-score matched for age, gender, race, and hearing loss-related conditions, including vascular disease and tobacco/nicotine use. Hearing loss risk in each cohort were compared against age-matched non-diabetic subjects. RESULTS: All diabetic patients had greater risk of SNHL compared to age-matched controls; having a higher HbA1c (≥14.0%) additionally associated with greater risk than a lower HbA1c (8.0-13.9%) for all age groups except 21-30 and 31-40 years. Furthermore, risk was higher for older patients of both HbA1c ranges, with patients ≥71 years at diagnosis having greatest risk. Patients ≥71 with HbA1c ≥14.0% (n = 3,870) had a 0.51% (95% confidence interval: 0.28-0.74, p < 0.0001) greater hearing loss risk, and patients with HbA1c 8.0-13.9% (n = 155,066) had 0.24% (0.22-0.27, p < 0.0001) greater risk. CONCLUSION: Type 2 diabetes diagnosis appears to strongly associate with greater risk of developing SNHL, especially in older patients. Audiometric screening may be warranted.