In 1938 before the American Otological Society I reported some observations on the loudness of tinnitus and its role in accentuating deafness. Last year I reported on the masking of tinnitus. Cases were demonstrated by audiograms showing tinnitus in different frequency bands masked by pure tones at or slightly above the intensity of the tinnitus. Also demonstrated were cases in which it required 40 to 50 decibels above threshold hearing at the different frequencies to mask the tinnitus, and instances in which it was difficult and often impossible to mask the tinnitus with any applied frequencies or other masking noise. The explanation was offered that there are two kinds of tinnitus, vibratory and nonvibratory; that the first is easily masked; that the second is masked with difficulty, and that the ease of masking of nonvibratory tinnitus varies with the location of the lesions and with the accompanying deafness.
FOWLER EP. HEAD NOISESSIGNIFICANCE, MEASUREMENT AND IMPORTANCE IN DIAGNOSIS AND TREATMENT. Arch Otolaryngol. 1940;32(5):903-914. doi:10.1001/archotol.1940.00660020910007