HSPA4 and Hearing impairment: Thus, we found that SC of low frequency prior to a loud noise not only protected against AAT based on significant improvements in hearing impairment and an apparent reduction in OHC loss but also improved SGN survival following a noise-induced stress response via controlling mitochondrial function and ROS levels in rat SGNs, and we are the first to have demonstrated a new theory on the protection of SC against AAT in which the Hsp70/Bmi1-FoxO1-SOD signaling pathway was involved.