tympanum

A membranous external auditory structure, as in certain insects.

The ornamental recessed space or panel enclosed by the cornices of a triangular pediment.

A similar space between an arch and the lintel of a portal or window.

The diaphragm of a telephone.

An ancient tambourine or hand-drum, either with a single head like the modern tambourine, or with both front and back covered (the back sometimes swelled out as in a kettledrum), and beaten either with the hand or with a stick.

In anatomy and zoology: The ear-drum considered as to its walls, its cavity, and its contents.