Background Auditory functions among patients with type 2 diabetes mellitus (DM) are controversial regarding cochlear or neural changes and the relationship between these changes and serum level of glycosylated hemoglobin (HbA 1c %). Aim of the study The aim of the study was to investigate auditory dysfunctions in type 2 DM patients with poor versus good glycemic control. Materials and methods The present study was conducted on three groups: two diabetic groups with poor and good glycemic control (n = 18 and 14, respectively) based on serum HbA 1c % and one healthy control group (n = 30) matched with age, sex, and BMI. All participants were subjected to clinical assessment, audiometry, brainstem auditory evoked potential ( BAEP), and evoked acoustic emissions transient evoked otoacoustic emissions and distortion product otoacoustic emissions (TEOAEs and DPOAEs). Results Diabetic patients with poor glycemic control had significantly elevated hearing thresholds compared with other groups at low and high frequencies in audiometry (P 0.01 and P 0.001). They showed significantly prolonged absolute latency in wave I and interpeak latency ( III–V) in the BAEP test compared with other groups (P 0.001). DM patients with poor glycemic control had significantly low amplitudes at all frequencies in the TEOAE test, as well as at high frequencies (4 and 6 kHz) on the DPOAE test, compared with other groups (P 0.001 and P 0.05, respectively). There were significant correlations between HbA 1c % and interpeak latency III–V (r = 0.340, P = 0.004) on the one hand and overall response of TEOAE amplitude (r = −0.471; P = 0.000) on the other. Conclusion Diabetic patients with poor glycemic control had worse auditory dysfunctions on both cochlear and neural findings.