Input-voltage method of bone-conduction calibration.

Several methods have been proposed for calibrating the bone-conduction section of an audiometer. Because of its low cost and ease of implementation, the input-voltage method is attractive. Only one previous investigation has assessed this calibration method and found it to be lacking. With the availability of updated "required voltages," a reexamination of this calibration method was warranted. Audiometric corrections were determined for 21 combinations of audiometers and bone vibrators at five test frequencies with an artificial-mastoid system. These corrections were compared with those determined with the input-voltage method. The latter yielded corrections that agreed directly with or deviated no more than 5 dB from artificial-mastoid corrections 93.4% of the time and deviated by 10 dB only 6.6% of the time. The use of the input-voltage method for clinical calibration is advocated in the absence of an artificial mastoid.