Medical specialty dealing with the ear, nose, and throat (seelarynx, pharynx). The connection of these structures became known in the late 19th century. Otolaryngologists use an otoscope to examine the eardrum and a laryngoscope (developed in 1855) to inspect the larynx. They also test hearing and prescribe hearing aids. The operating microscope (developed in 1921) and flexible endoscopy now permit them to operate on delicate internal structures.