Katrien Vermeire1, David M. Landsberger2
1Department of Communication Sciences and Disorders, Long Island University Campus Brooklyn, New York, New York, USA
2Department of Otolaryngology, New York University School of Medicine, New York, New York, USA

Several studies have suggested that hearing loss in the older population is independently associated with poorer cognitive functioning. However, both cross-sectional and prospective studies have reported conflicting results. An explanation might be that the way they assess hearing impairment, via an audiogram, is a poor predictor of cognitive functioning. Pure-tone audiometry is a measure of pure-tone detection and not the ability to use sounds in a meaningful way. Therefore, an auditory measure that assesses ability to use instead of detecting auditory information might be more appropriate to assess hearing ability. Suprathreshold psychoacoustic tasks, such as measures of temporal resolution, have been proposed as better measures of hearing quality.

The aim of this study was to investigate the contributions of age, hearing ability as measured by standard audiometry, and temporal acuity to cognitive functioning in older adults. Sixteen older adults (between 60 and 80 years of age) with age-appropriate hearing participated in this study. Auditory processing was investigated using the Gaps in Noise (GIN) test which focusses on the temporal processing ability and is relatively independent of audibility measures. Cognitive functioning was measured using working memory tests. Verbal working memory was tested using a Reading Span Test. A Corsi Block Tapping Test was used to test the Visuo-Spatial modality of the working memory.

Temporal processing ability (as measured by the GIN) was correlated with performance on the tests of verbal and visuo-spatial working memory. However, neither age nor audiometric hearing thresholds correlated with the working memory metrics.  Furthermore, multiple linear regressions found no additional benefit of including age or thresholds as part of the model. The data suggests that the ability to process auditory information may be more linked to cognitive function than the ability to detect auditory signals as is typically used to evaluate hearing loss.