An investigation of the validity of high-frequency audition

In this investigation, a masking experiment was utilized to explore the validity of high-frequency audition. Threshold shifts produced by a narrow-band noise with sharp filter slopes and variable center frequency were determined for pure-tone stimuli from 8000 to 14 000 Hz. Subjects were young adults with normal hearing from 250 through 8000 Hz, and with high-frequency thresholds comparable to those obtained in a previously conducted normative survey. After pure-tone thresholds were obtained for each test frequency, a narrow-band masker was presented ipsilateral to the pure-tone stimulus with center frequency equal to the pure tone. The masker was adjusted to an intensity level necessary to shift the pure-tone threshold approximately 17 dB. The center frequency of the masker was then decreased in discrete steps with the pure-tone threshold re-established at each step. The experimental results, as demonstrated by release-from-masking functions, are consistent with the expectation of increased masker effectiveness as the center frequency of the masker approximates the test frequency. The findings of this investigation suggest that responses to high-frequency auditory stimulation are the result of high-frequency perception, and not the perception of some lower frequency distortion process.