eardrum vs tympanum

eardrum

noun
  • A thin membrane that separates the outer ear from the middle ear and transmits sound from the air to the malleus. 

tympanum

noun
  • The eardrum (tympanic membrane, membrana tympanica). 

  • A drum-shaped wheel with spirally curved partitions by which water is raised to the axis when the wheel revolves with the lower part of the circumference submerged; used for raising water, as for irrigation. 

  • A membranous resonator in a sound-producing organ in frogs and toads. 

  • A thin tense membrane covering the hearing organ on the leg or body of some insects, sometimes adapted (as in cicadas) for producing sound. 

  • (in certain birds) The labyrinth at the bottom of the windpipe. 

  • A vertical recessed triangular space between the sides of a pediment, typically decorated 

  • The recessed triangular space within an arch, and above a lintel or a subordinate arch, spanning the opening below the arch 

  • The main portion of the middle ear: the tympanic cavity (cavitas tympani). 

How often have the words eardrum and tympanum occurred in a corpus of books? (source: Google Ngram Viewer )