Pf. Hong Ju Park is an internationally recognized otologist with expertise in hearing loss and vestibular disorders, who works as a professor at Department of Otorhinolaryngology-Head & Neck Surgery, Asan Medical Center. His practice focuses on three topics. One is the management of hearing loss and evaluation of brain cortical changes by hearing loss, and the others are balloon dilation and development of stent for Eustachian tube dysfunction, and management of vestibular disorders.