Loudness Balance Methods for Earphone Response Measurement
Daniel W. Martin, Martin L. Touger · The Journal of the Acoustical Society of America · 1950
Simple procedures are given for the subjective measurement of earphone response by two methods. The first method, which is rather widely recognized, requires the subject to match the loudness of an earphone tone to the loudness of a free-field reference tone of the same frequency. Interpretation of the data from this test is direct, but the facilities, technique, and time required are considerable. A second method, less widely used, involves the loudness balancing of an earphone tone of variable frequency to that of an earphone reference tone of fixed frequency and level. This method is much simpler, and can be used to measure earphone performance under circumstances where the first method is virtually impossible. However, the interpretation of the test data is less direct. This paper is an analysis of the two methods which attempts to develop a correspondence between the data obtained by the two methods.