an instrument to aid hearing, such as an ear trumpet or hearing aid

listen to the pronunciation of an instrument to aid hearing, such as an ear trumpet or hearing aid
İngilizce - İngilizce
otacousticon

Gyges' invisible ring, or some rare perspective glass, or otacousticon, which would so multiply species that a man might hear and see all at once .

an instrument to aid hearing, such as an ear trumpet or hearing aid