Small square ear trumpet, hearing aid, European, 1869-1900

This hearing aid is probably a variation of a ‘London Dome’ ear trumpet. It is so-called because of its similarity to the dome on St. Paul’s Cathedral. The ivory ear tip sat inside the ear canal. The ear trumpet amplified sounds down the tube. The ear trumpet is a type of parabolic reflector. This reflective device projects energy onto a focal point, in this case the ear drum, through refraction and reflection. This enables the ear trumpet to be an effective hearing aid while remaining relatively small.