Vibration perception threshold assessments: Comparing the Staircase and von Békésy methods

Vibration perception thresholds (VPTs) are used in fields like health, work, and traffic safety. To assess them, international standards recommend two psychophysical methodologies: the von Békésy method, or variants of the up and down algorithm, for example, the Staircase method. However, their impact on the results of threshold measurement has not been explored much, including on assessments at frequencies > 250 Hz. Thus, this study compared VPT results obtained by the two methods to determine what differences could be found between them. Using the Staircase (3 Down/1 Up rule) and von Békésy methods, VPT assessments were conducted at the pulp of the right index and ring fingers of 30 healthy subjects, at vibration frequencies of 250 Hz, 375 Hz, and 500 Hz. Analysis revealed significant differences between the mean VPTs across the three frequencies, regardless of method (VPTs increasing as frequency increased). Significant differences were also found between results from both methods (lower thresholds with Staircase). Significant differences were further found between VPT results assessed at the index and ring fingers (lower on the latter). However, this was only verified in results obtained using the Staircase. These findings highlight the importance of method selection during experimental design and when interpreting or comparing findings between studies using different VPT assessment techniques. All data related to the study presented in this paper is available at the Open Science Framework (OSF), at the following URL: https://osf.io/3uqsb/overview?view_only=03e228c15a274cb781045e3b61ccb052 . This study was not preregistered.