Warbled Tone Masking in Bone-Conduction Audiometry

Abstract

Warbled tones are compared with narrow-band, wide-band, and complex noises with respect to their efficacy as air-conducted maskers. Bone-conducted pulsed tones of 500, 1000, 2000, and 4000 Hz were presented to the foreheads of eight normal-hearing subjects. With each masker presented binaurally and held constant at a nominal 40-dB level (re normal threshold for each noise) the results indicated that the effectiveness of the warbled tone was essentially comparable to that of the narrowband noise and was significantly better than the wide-band and complex noises over all frequencies combined. Some variation in efficacy was noted, however, as a function of individual frequencies. These results, plus those of the inter- and intra-subject reliabilities and the relative variabilities of the obtained masked thresholds, indicated that a warbled tone may have potential clinical usefulness as a masker.