In the February issue of this journal, Bunch1 gave a number of charts showing a comparison of the results of acuity tests of hearing taken by two different types of audiometer. These types were the 1-A audiometer, manufactured by the Western Electric Company, and the pitch range audiometer, developed at the State University of Iowa. They were called the "A" and "B" audiometers, respectively, a designation which will also be used in this paper.
As a large number of audiograms have been published by Dean and Bunch, together with the clinical history of the cases, it occurred to me that it would be of assistance to those otologists who are using sensation units in plotting audiograms to be able to redraw the audiograms of Dean and Bunch on the new scale. For this purpose, a set of calibration curves has been deduced from the results published by
FLETCHER H. COMPARISON OF THE RESULTS MADE WITH TWO TYPES OF AUDIOMETER. Arch Otolaryngol. 1926;4(1):51–57. doi:10.1001/archotol.1926.00590010061006