Auditory Temporal Resolution in Individuals with Diabetes Mellitus Type 2

Exploring auditory temporal resolution and dichotic listening skills among individuals with type 2 diabetes mellitus

The study aimed to explore the auditory temporal resolution and dichotic listening skills in patients with type 2 diabetes mellitus (T2DM) and identify associated health-related factors. Using a cross-sectional design, 87 adults with T2DM and 48 non-diabetic controls, all with normal hearing, participated. The two central auditory processing (CAP) skills were assessed through the Gaps-In-Noise (GIN) and Dichotic-Digits Listening (DDL) tests. T2DM participants underwent blood tests to measure various health-related factors. In the GIN test, the shortest gap threshold (GapTh) obtained across both ears was significantly higher in the diabetic group (9.1 ± 2.4 ms) compared to the non-diabetic group (7.5 ± 1.5 ms), and the score of correctly identified gaps (GapSc) in the diabetic group (45±11 %) was significantly lower than GapSc in the non-diabetic group (52±9 %), p < 0.001. In the DDL test, the free-recall score (73.8 ± 18.5 %) across both ears and the right-ear advantage (-1.3 ± 20.6 %) in the diabetic group were significantly lower than the free-recall score (85.8 ± 11.9 %) and right-ear advantage (6.9 ± 11.9 %) in the non-diabetic group, p < 0.005. Furthermore, the duration of diabetes, eGFR level, retinopathy, carotid plaque, fasting blood glucose level, and HDL-C (good cholesterol) level were factors significantly associated with performances in the GIN and/or DDL tests for T2DM participants. In conclusion, individuals with T2DM are at risk of reduced auditory processing skills in temporal resolution and dichotic listening, impacting their speech understanding. Six health-related factors were identified as significantly associated with CAP skills in T2DM patients.

Behavioral assessment of auditory processing in adulthood: population of interest and tests - a systematic review

PURPOSE

To identify the behavioral tests used to assess auditory processing throughout adulthood, focusing on the characteristics of the target population as an interest group.

RESEARCH STRATEGIES

PubMed, CINAHL, Web of Science, and Scielo, databases were searched with descriptors: "auditory perception" or "auditory perception disorders" or "auditory processing" or "central auditory processing" or "auditory processing disorders" or "central auditory processing disorders" with adults OR aging.

SELECTION CRITERIA

Studies with humans included, the adult population from 18 to 64 years old, who performed at least one behavioral test to assess auditory processing in the absence of hearing loss.

DATA ANALYSIS

Data extraction was performed independently, using a protocol developed by the authors that included different topics, mainly the behavioral auditory tests performed and the results found.

RESULTS

Of the 867 records identified, 24 contained the information needed to answer the survey questions.

CONCLUSION

Almost all studies were conducted verify performance in one or two auditory processing tests. The target target population was heterogeneous, with the most frequent persons with diabetes, stuttering, auditory processing disorder, and noise exposure. There is little information regarding benchmarks for testing in the respective age groups.

Impaired auditory neural performance, another dimension of hearing loss in type-2 diabetes mellitus

AIM

to evaluate auditory performance in subjects with poorly controlled type-2 diabetes mellitus, using a simple test battery assessing sensitivity to pure tones and neuronal function.

METHODS

Enrolled subjects, aged between 23-79 years, reported several auditory dysfunctions. They were tested using pure-tone audiometry, otoacoustic emissions for cochlear-function evaluation, and measurement of middle-ear muscle-reflex thresholds in search of an auditory neuropathy.

RESULTS

Compared to the standard established for an age-matched normative population, the distribution of averaged pure-tone thresholds in enrolled subjects shifted by about one standard deviation with respect to the normal distribution, in line with past reports of mild sensorineural hearing impairment in diabetes, even though many diabetic subjects fell well within the normative interval of audiometric thresholds. Otoacoustic emissions showed that pure-tone thresholds correctly predicted the status of cochlear sensory cells that, by amplifying sound, ensure normal hearing sensitivity. Whereas the observed hearing losses should not have affected the acoustic levels above which the protective middle-ear muscle reflex is triggered by intense sounds, this reflex was undetectable in around 40% enrolled subjects, a marker of auditory neuropathy.

CONCLUSION

auditory-neural function should be evaluated to identify diabetic subjects whose hearing is impaired. Simple automatic tests are available for this purpose, for example middle-ear muscle reflex detection, which turns out to be more sensitive than the standard audiogram.

Diabetes and Auditory-Vestibular Pathology

The relationship between diabetes mellitus (DM) and the auditory/vestibular system has been investigated for more than a century. Most population-based investigations of hearing loss in persons with diabetes (PWD) have revealed a slow progressive, bilateral, high-frequency sensorineural hearing loss. Despite the growing research literature on the pathophysiology of DM-related hearing loss using various animal models and other human studies, knowledge of specific mechanism of the degenerative changes of the inner ear and/or auditory nerve is far from full elucidation. Recent investigations of the mechanisms underlying the association between hearing loss and DM suggest complex combined contributions of hyperglycemia, oxidative stress resulting in cochlear microangiopathy, and auditory neuropathy. An even lesser understood complication of DM is the effect on the vestibular system. Here we provide an overview of animal and human evidence of pathophysiological changes created by DM and its effects on auditory-vestibular anatomy and function.

Speech evoked auditory brainstem response and gap detection threshold in middle-aged individual

This study aimed at characterizing the gap detection threshold (GDT) and speech evoked ABR (SABR) in younger and middle-aged individuals. Two groups of subjects were participated in the study which includes 15 young adults in the age range of 15-25 years and 15 middle-aged individuals in the age range of 40-60 years. SABR with stimulus/da/of 40 ms and GDT were investigated on both groups. For SABR, Mann-Whitney U test revealed that ageing has significantly adverse effect on the encoding of F1 and F2 at brainstem level. However, no significant effect of ageing (till middle age) on the encoding of F0 was observed in present study. Mann-Whitney U test also showed significant longer latency of wave V in middle-aged individuals compared to younger adults. Furthermore, GDT was significantly better in younger adults compared to middle-aged individuals according to Mann-Whitney U test. This study also revealed no significant correlation between GDT and F0, F1, F2 for younger as well as middle-aged individuals. The findings of this study showed poor encoding of certain aspects of speech at brainstem level in middle-aged individuals compared to younger adults. This study also revealed deterioration of auditory processes in middle-aged individuals.