Abstract:
Diabetes is one of the most prominent health emergencies of the 21st century, affecting millions of people worldwide. An estimate of 415 million individuals had diabetes in 2015, with more than 10% of those individuals living in the Sub-Saharan Africa region. Diabetes is classified according to aetiology. Diabetes mellitus type II accounts for more than 90% of cases. Since the disease is initially asymptomatic, 30% to 85% of cases remaining undiagnosed. Due to this delay in diagnosis approximately 20% of the individuals will have developed secondary complications. Auditory complications are often associated with diabetes; however, the extent and nature of these auditory manifestations are still unknown.
The main aim of this study was to determine and compare the temporal resolution abilities of adults with diabetes mellitus type II with normal pure tone thresholds to the findings of healthy age and gender matched controls without diabetes mellitus type II.
A descriptive between-group comparative research design was utilized in this study. Purposive convenience sampling was employed to recruit individuals with and without diabetes mellitus type II.
Fifty-six age and gender-matched participants (28 diabetic, 28 non-diabetic) between the ages of 20 to 60 years participated in the study. Pure tone audiometry was used to determine hearing thresholds while temporal resolution abilities, specifically the gap detection threshold, were determined using the GIN test and the RGDT. Psychometric functions were also constructed to determine differences between the two participant groups in terms of gap detection threshold as a function of gap duration (GIN test).
A statistically significant difference of p<0.001 was obtained for the mean gap detection threshold between the two groups for the GIN test. No significant differences were obtained for the total percentage correct scores between the two groups. Results for the RGDT regarding the arithmetic mean gap detection thresholds indicated no statistically significant difference (p=0.101) between the diabetic group and the non-diabetic group at all test frequencies. Finally, psychometric functions constructed for the participant groups with and without diabetes type II revealed that the gap durations that best distinguish the two groups are 5, 6 and 7 ms
Evidence of the present study suggests a strong association between diabetes mellitus type II and temporal resolution abilities (gap detection threshold). As temporal resolution is closely linked to speech in noise, more studies are needed in this regard.
