Silver ear trumpets, six parts, telescopic, by Hawksworth Eyre and Co., Sheffield, 1845 Telescopic ear trumpet Audiology 1845
One of eight "Emitome" hearing aids with box; components of some of these being produced on NV-10-H injection moulding machine "Emitome" hearing aid Plastics and Modern Materials
One of eight "Emitome" hearing aids; components of some of these being produced on NV-10-H injection moulding machine "Emitome" hearing aid Plastics and Modern Materials
Walking stick hearing aid, by Franck Valery Freres, Paris, 1860-1910 Walking stick hearing aid Audiology 1860-1910