A powerful article in Frontiers in Neuroscience reported that hearing aid use reversed the negative effects on brain function caused by untreated hearing loss. Brain function was measured by recording cortical evoked potentials.
The subjects also experienced significant improvements in speech perception in noise and cognitive performance. The researchers concluded:
These results provide preliminary evidence that . . . restored audibility with hearing aids may reverse compensatory changes in cortical resource allocation (caused by untreated hearing loss).