The field of aural tinnitus has escaped extensive scientific study primarily because no method of objectively studying this subjective symptom has been available. This paper is a preliminary report of a method that I have developed for the measurement of the pitches and intensities of tinnitus, and of some of the findings.
The point of departure in this study was the observation that when a sound of the same fundamental pitch as the tinnitus is superimposed on the ear, a masking of the superimposed note by the tinnitus is found, instead of a summation of intensities ; one would not expect this result if the mechanism of tinnitus and of hearing of sound from the outer world were similar. In a fairly large series of cases it was found that the intensity of the superimposed sound required for hearing of the sound, above the normal threshold for that frequency, constitutes a
JOSEPHSON EM. A METHOD OF MEASUREMENT OF TINNITUS AURIUM. Arch Otolaryngol. 1931;14(3):282–283. doi:10.1001/archotol.1931.00630020322004