Investigation of cortical and subcortical plasticity following short-term unilateral auditory deprivation in normal hearing adults

There is growing evidence that auditory stimulation or deprivation can induce physiological and perceptual changes in the auditory system of normal hearing adults. The present study investigated cortical (hemispheric asymmetry) and subcortical (acoustic reflex threshold) changes in 11 normal hearing adults after 7 days of continuous unilateral earplug use (around 30 dB of attenuation at the high frequencies). The results revealed(a) a decrease in high frequency acoustic reflex thresholds of around 7 dB in the ear that had been plugged and (b) no change in hemispheric asymmetry. The change in acoustic reflex is consistent with subcortical plasticity. It is unclear if homoeostatic plasticity preserved the normal hemispheric asymmetry or if this is the result of the experimental paradigm.