Audiologists are professionals with a master’s or doctorate degree in audiology, the study of hearing. They specialize in testing, evaluating and treating hearing loss and balance disorders, including the fitting of hearing aids. Hearing Instrument Specialists are trained in fitting and dispensing hearing aids. Hearing Instrument Specialists undergo extensive educational and clinical training and are often state-licensed and board-certified to test for hearing loss and fit hearing aids. Otolaryngologists are medical doctors that specialize in the diagnosis and treatment of ear, nose, throat, head and neck disorders. Otolaryngologists are also known as ENT doctors.