Otology is the medical specialty or subspecialty that deals with conditions within the ear. Otology, in a broader sense, encompasses all aspects of ENT diseases. An otologist typically does not master both surgical and diagnostic aspects of ENT because they often take a rigorous postgraduate course in either one or even both areas.
If you're interested to know more about the various specialties within general Otolaryngology, these are some options available to choose from: Laryngologist, rhinologist, surgeon/laryngectomee specialist (Laryngeal & Pulmonary Surgeon), head & neck reconstructive surgeon/microsurgeon(HNS) - this would be for craniofacial and maxillofacial surgeons.
You can read more about these ENT specialties on the "Adventis ENT Head Neck and Cochlear Implant of Otolaryngology-Head and Neck Surgery" website.