The cancellation method for an accurate determination of an air-bone gap

Abstract

For a reliable detection of the bone conduction threshold blocking of the contralateral ear can be necessary but then the noise will affect the threshold in the test ear. To resolve this problem the cancellation method is used. The equalization of air and bone conduction sound level in the inner ear is very accurate, the relation between the intensities has been proved to be linear and independent of noise at the contralateral ear. An application for calibration of the bone conduction vibrator to the head phone is discussed. The benefit of the method for measuring an air-bone gap in an accurate way in patients suffering bilaterally from a severe conductive hearing loss is shown.

Simultaneous cancellation of air and bone conduction tones at two frequencies: Extension of the famous experiment by von Békésy

“…The masking may affect the subjects' abilities to achieve optimal cancellation settings. Kapteyn et al (1980) reported that contralateral noise up to 70 dB HL did not disturb their cancellation adjustment. At the highest levels in this study (60 dB HL), the noise level was probably between 70 and 80 dB SPL.…”