CHICAGO LARYNGOLOGICAL AND OTOLOGICAL SOCIETY, MIDDLE SECTION OF THE AMERICAN LARYNGOLOGICAL, RHINOLOGICAL AND OTOLOGICAL SOCIETY: Joint Meeting, Jan. 9, 1929

Abstract

SOMEVERYACCURATEMEASUREMENTS OF THEAMPLITUDE OFVIBRATION OFTUNINGFORKPRONGS.DR.ROBERTSONNENSCHEIN. To have accurate methods in all functional testing of hearing, it is necessary that the instruments one uses, such as tuning forks, be properly calibrated; to obtain uniform and comparable observations, a definite technic must be employed. In the work done with the Webster phonometer some years ago, it was found that apparently the greatest intensity of vibration emanated from the broad or outer surface of the prongs, a little less so from the narrower surfaces, still less from the ends, and least of all from the edges or angles formed by the broad and narrow surfaces. Some forks have prongs which show a quadrilateral cross section so that one cannot say a broad or outer surface if the outer surface and the anterior surface are the same width. At the time that the