Effect of static force on bone conduction hearing thresholds and comfort

Abstract
To assess the effect of the static force of a bone vibrator on the results of bone conduction (BC) threshold measurements and comfort. BC thresholds were determined for 40 participants using the standardized P-3333 headband and a leather adjustable headstrap with variable static forces (2.4, 3.4, 4.4, 5.4 N). Comfort ratings were examined using a five-point Likert scale. Mean BC thresholds were within ± 2 dB across all conditions; differences may be considered small enough to be clinically insignificant. Participants experienced significantly greater discomfort with the P-3333 versus the adjustable headstrap. The mean static force of the P-3333 varied considerably and was higher in situ than the calibration standard of 5.4 N. The results suggest that future revisions of relevant international and national standards should address the use of an adjustable headstrap and a static force less than 5.4 N.