The relationship between tinnitus pitch and the edge frequency of the audiogram in individuals with hearing impairment and tonal tinnitus

Abstract

Some theories of mechanisms of tinnitus generation lead to the prediction that the pitch associated with tonal tinnitus should be related to the "edge frequency" of the audiogram, f(e), the frequency at which hearing loss worsens relatively abruptly. However, previous studies testing this prediction have provided little or no support for it. Here, we reexamined the relationship between tinnitus pitch and f(e), using 11 subjects selected to have mild-to-moderate hearing loss and tonal tinnitus. Subjects were asked to compare the pitch of their tinnitus to that of a sinusoidal tone whose frequency and level were adjusted by the experimenter. Prior to testing in the main experiment, subjects were given specific training to help them to avoid octave errors in their pitch matches. Pitch matches made after this training were generally lower in frequency than matches made before such training, often by one or two octaves. The matches following training were highly reproducible. A clear relationship was found between the values of f(e) and the mean pitch matches following training; the correlation was 0.94. Generally, the pitch matches were close in value to the values of f(e).