Evaluation of speech recognition in noise in patients with type 2 diabetes mellitus in a tertiary care hospital – a cross-sectional analytical study

Introduction: Type 2 Diabetes Mellitus (T2DM) is associated with multiple systemic complications, including vascular and neuropathic changes that can affect the auditory pathway. These alterations may contribute to hearing loss and difficulty in speech perception, particularly in noisy environments. This study aimed to evaluate speech recognition in noise among patients with T2DM using the Signal-to-Noise Ratio 50 (SNR50), and to examine its relationship with disease duration and glycemic control. Methods: An analytical cross-sectional study was conducted at a tertiary care hospital. Ninety subjects aged 30–60 years were recruited, comprising 45 patients with T2DM and 45 age-matched non-diabetic controls. All participants underwent audiological evaluation including Pure Tone Average (PTA), Tympanometry, Speech Reception Threshold (SRT), Speech Identification Score (SIS), Uncomfortable Loudness Level (UCL), and SNR50 testing. Data were analysed to assess differences between groups and correlations with diabetes duration and glycemic control (HbA1c levels). Results: PTA values were higher in patients with T2DM compared to controls, indicating worse peripheral hearing. Diabetic patients demonstrated poorer speech perception, confirmed by elevated SRT values. SNR50 values were significantly impaired in T2DM patients relative to controls. Longer duration of diabetes (>10 years) was associated with reduced SIS and higher PTA and SRT values compared to patients with 5–10 years of disease. A statistically significant positive correlation was observed between SNR50 and duration of diabetes. While PTA, SRT, and SIS did not show significant variation across HbA1c categories, SNR50 values worsened significantly with poorer glycemic control. Conclusion: T2DM is associated with impaired speech perception and poorer hearing outcomes, with disease duration exerting a cumulative adverse effect. SNR50 performance was significantly related to glycemic control, suggesting that subtle central auditory dysfunction may coexist with or precede peripheral hearing loss in diabetic patients. Early evaluation of auditory function in T2DM may aid in timely identification and management of communication difficulties.