Ear-trumpet definition

If an ear-trumpet is placed at the focus of the second mirror the ticking may be heard easily, though it is quite inaudible by direct waves.

He suggested the use of experimental tanks for testing the powers of ship models, invented an ear-trumpet for the deaf, improved the common house-stove of his native land, cured smoky chimneys, took a lively interest in machine-guns and even sketched a flying machine.

At a station more than 13 kilometres away a sort of big ear-trumpet, closed by a membrane, was placed with the membrane under water, the tube rising above the surface.