Technical Details
This piece of apparatus is called an Otophone and was designed by Marconi engineers in 1922, to be an aid for the deaf. The Marconi Otophone consists of an attache case type container, a microphone on a small ebonite stand, valve amplifier, and an earpiece. The earpiece is connected to the instrument by a length of flexible cord to enable the wearer to sit some distance away, and the microphone, mounted on a pedestal is easily moved around. The container need not be moved and so can remain on the floor by the user. The container holds a two-valve voice amplifier, together with the necessary batteries. Any sound within ten to fifteen feet of the unit could be usually heard quite well. At lectures where the speaker's voice is raised, the unit could be as much as ten times this distance from the speaker and still give extremely strong audibility. Several deaf people could use the unit by the addition of extra headphones. The purpose of the Marconi Otophone was not to give an excessively powerful effect on the ears, but to have a strong enough effect to enable a person with hearing problems to hear general levels of conversation.