Auditory training improves neural timing in the human brainstem

Transient and sustained (frequency-following response) components of the brainstem response were evaluated. The primary pathway afferent volley - neural events occurring earlier than 11 ms after stimulus onset - did not demonstrate plasticity. However, quiet-to-noise inter-response correlations of the sustained response (∼11-50 ms) increased significantly in the trained children, reflecting improved stimulus encoding precision, whereas control subjects did not exhibit this change. Thus, auditory training can alter the preconscious neural encoding of complex sounds by improving neural synchrony in the auditory brainstem. Additionally, several measures of brainstem response timing were related to changes in cortical physiology, as well as perceptual, academic, and cognitive measures from pre- to post-training.