Is Cognitive Function in Adults with Hearing Impairment Improved by the Use of Hearing Aids?

OBJECTIVES In the present study, we investigated whether speech-related cognitive function and speech recognition ability under background noise in adults with hearing impairment are improved with the use of hearing aids. METHODS Participants were recruited from the ENT Department of Eulji Hospital from September 2008 to July 2009. The study group comprised 18 participants (mean age, 69.5±8.3 years) with sensorineural hearing loss who were fitted with hearing aids, and the control group comprised 11 participants of equivalent age (mean age, 63.1±11.8 years) who were not fitted with hearing aids. All participants were assessed using the computerized Korean visual verbal learning test (VVLT) and words-in-noise (WIN) test prior to fitting of hearing aids for the study group and initially for the control group. Both groups were reassessed in both tests after 6 months. For each group, differences in the results between the two assessments were compared using the Friedman test. RESULTS There was no difference in mean age between the study group and control group. In the study group, total VVLT score (reflecting short-term memory) was significantly improved from before hearing aid use to 6 months after hearing aid use (P<0.05), and VVLT recognition score (reflecting learning ability) was also significantly improved from before hearing aid use to 6 months after hearing aid use (P<0.05), but there was no change in the control group. For VVLT latency score (reflecting efficiency of memory) and speech discrimination score in the WIN test, no statistically significant difference was found between the initial and 6-month assessments in the study group or in the control group (P>0.05). CONCLUSION The speech-related cognitive function of individuals with hearing impairment improved after using hearing aids. This finding indicates that hearing aids may induce acclimatization of the central auditory system.