Warble tone as an audiometric stimulus.
Pure-tone and warble-tone thresholds were compared for 198 normal-hearing inexperienced adult listeners at six frequencies at octave intervals from 250 through 8000 Hz. Results of the analysis of variance procedures showed statistically significant differences (p less than 0.01) for the test frequencies 500, 2000, 4000, and 8000 Hz. Although significant differences were found at four of the six test frequencies, mean differences were quite small, the largest being 2.3 dB at 8000 Hz. This finding is thought to support the notion that the audiologist may use warble tone with stimulus parameters up to and including frequency deviations of +/- 5% with modulation rates of five per second to measure thresholds, which are directly comparable to pure-tone thresholds for patients with normal hearing and those with relatively flat hearing loss.