The Pamphlet Collection of Sir Robert Stout: Volume 38
Historical. — Origin of the Audiphone
Origin of the Audiphone.
A Device for Removing the Misery of the Desti—Discovery of an Entirely New Principle in Acoustics.
The ingenuity of American inventors has displayed itself for many years in the patenting of instruments to help the hearing of different people. All these devices are but modifications of the ear-trumpet. They have all been attempts to remedy, through the ear, a defect existing within it, and many of them have undoubtedly rather worsened than bettered in its sense the constant use of thè defective organ;, and the throwing upon it of a greater volume of sound than it is naturally accustomed to has a tendency to increase the disease which has affected the hearing.
An inventor has now come forward, however, who has struck out on a new path; who has discarded the ear as the means of hearing, and putting on one side all those ear- trumpets, large and small, which are bothersome to carry around, and which really are only available when a speaker talks directly into them, and which are practically useless if listening at a public meeting, theatre, or an opera, and has utilized the mouth—or, to speak more directly, the teeth—as a means of making the deaf hear. It is the application of a long-known principle, but none the less- ingenious, and none the less useful for that. The inventor is a Chicagoan—Mr. Richard S. Rhodes, the senior partner of the publishing firm of Rhodes & McClure. He has been deaf for nearly twenty years. After going through, with the usual routine of ear-trumpets, and all that sort of nonsense, and getting thoroughly disgusted with it, he happened one day to hold a watch between his teeth, and page 9 noticed that he could distinctly hear its ticking, though, when he held it to his ear no sound was audible. This set him to thinking that possibly he might be able to invent some device by which the sounds of the human voice could be transmitted to the auditory nerve, through the medium of the tube, just as the ticking of the watch had been. So he launched out upon a series of experiments, extending over many years, and costing not a little, which finally brought him to an assured success. He began by taking strips of wood, say eight by nine inches each way, and, by holding the upper end of the strip against his teeth—the strip being so placed that the voice of the person to whom he was speaking should strike upon it, and the vibrations imparted to it by the voice might be given to his teeth, and thus pass to the auditory nerve, he found that he was able to hear, but that the wood was too resonant. The sound thus obtained echoed too much. Those echoes run into one another so that the hearer hears a sound and nothing more. These experiments of wood were very thorough, extending over a hundred different kinds in as many different ways. Then he resorted to metal, trying tin, silver, steel, and brass, but with equally unsatisfactory results. He got the sound, but it was too hollow. He tried compositions of paper, and everything else imagination could suggest, until about a year ago he hit upon vulcanized rubber, and found that that article—which had not the resonance of many of the other things which he had tried—was the most satisfactory. Having convinced himself that that was the best medium for conveying sounds, he then had to go through another series of experiments to decide as to the best shape, and manner of using it. That problem he worked out to his satisfaction; and, having convinced himself of his success, applied for letters-patent, for what he calls an Audiphone, or a sound hearer.