Bone conduction thresholds for different mastoid placement sites

Abstract

Bone conduction thresholds were obtained from 250 to 4000 Hz by placing the bone vibrator on the mastoid as done for audiometry and at mastoid sites initially judged to produce the loudest perception of a 250-, 500-, and 1000-Hz pure tone and white noise using 30 normally hearing adult subjects. The bone conduction thresholds were found to be variable across placement sites and test frequencies. However, the placement site judged to be the loudest with white noise generally resulted in the lowest thresholds. Implications for bone conduction audiometry, including normal air-bone gaps, and reference equivalent threshold force levels will be discussed.