Auditory-cognitive markers of mild cognitive impairment: Evidence from a systematic review

Mild Cognitive Impairment (MCI) represents an intermediate stage between normal aging and dementia. Emerging evidence suggests that central auditory processing (CAP) deficits may appear even earlier and serve as sensitive indicators of cognitive decline. The literature was reviewed to examine the CAP abilities in individuals with MCI. It also examines existing MCI diagnostic guidelines from various countries to assess how CAP assessments are currently integrated in clinical protocols. A systematic literature search was conducted using PubMed/Medline, Cochrane Library, Scopus and Google Scholar (Jan 2014–Dec 2024). Key search terms included “temporal resolution,” “dichotic,” “speech-in-noise,” “auditory working memory,” “central auditory processing disorder,” “auditory scene analysis,” “temporal gap detection,” “auditory discrimination,” and “mild cognitive impairment.” Only those studies were shortlisted if they investigated CAP in elderly individuals with MCI. Articles outlining MCI diagnostic guidelines were also considered. Twenty-nine articles met the inclusion criteria. Twenty-three indicated a significant CAP deficit in persons with MCI. Studies consistently show MCI is associated with CAP impairments. Tests like Gap Detection Threshold, Dichotic Digit Test, Sentence-in-Noise, and Digits Backward effectively distinguish MCI patients from healthy controls. Six articles focused on diagnostic guidelines from various countries. Despite many studies showing CAP deficits in MCI, leading diagnostic guidelines do not include CAP tests. CAP tests hold promise for the early detection of MCI. Integrating them into clinical guidelines can improve diagnostic sensitivity which may delay its progression to Alzheimer’s disease. Despite their diagnostic utility, such tests are not included in the MCI diagnostic frameworks.