Otolaryngology is the branch of medicine that specializes in the diagnosis and treatment of ear, nose, throat, and head & neck disorders.
The full name of the specialty is otolaryngology-head and neck surgery. Practitioners are called otolaryngologists-head and neck surgeons, or sometimes otorhinolaryngologists (ORL).
A commonly used term for this specialty is ENT (ear, nose and throat).
See Wikipedia, Otolaryngology.