Difference thresholds for the perception of whole-body vertical vibration: dependence on the frequency and magnitude of vibration

Abstract

When seeking to reduce vibration in transport it is useful to know how much reduction is needed for the improvement to be noticeable. This experimental study investigated whether relative difference thresholds for the perception of whole-body vertical vibration by seated persons depend on the frequency or magnitude of vibration. Relative difference thresholds for sinusoidal seat vibration were determined for 12 males at three vibration magnitudes and eight frequencies (2.5, 5, 10, 20, 40, 80, 160, 315 Hz) using the three-down-one-up method in conjunction with a two-interval-forced-choice procedure. The median relative difference thresholds were in the range 9.5% to 20.3%. There appeared to be a frequency-dependence at the lowest vibration magnitude, such that higher frequencies had higher difference thresholds. The relative difference thresholds depended on the vibration magnitude only at 2.5 and 315 Hz. The influence of both vibration frequency and vibration magnitude on the measured difference thresholds suggests that vision (at 2.5 Hz) and hearing (at 315 Hz) contributed to the perception of changes in vibration magnitude.

Perceptual Thresholds for Vibration Transmitted to Road Cyclists

“…Bellmann (2002) reported Weber fractions between 15% and 20% for 10, 20, and 40 Hz when using vertical vibration at 0.063 m/s 2 RMS. Forta et al (2009) reported Weber fractions between 9.5% and 20.3% for vertical whole-body vibration of seated participants with frequencies ranging between 2.5 and 315 Hz.…”

“…To our knowledge, there are no studies available about perceptual thresholds for whole-body vibration using transmitted power, especially in the context of road cycling, with the exception of preliminary findings of the present study (Ayachi, Champoux, Drouet, & Guastavino, 2016). JNDLs for whole-body vibration have been reported in the literature in terms of acceleration (e.g., Bellmann, 2002; Forta, Morioka, & Griffin, 2009; Matsumoto, Maeda, & Oji, 2002). Most of the studies measured JNDLs for whole-body vibration using sinusoidal excitation with participants sitting on a car seat or a rigid flat seat.…”

Investigating the Effect of Sensory Concurrency on Learning Haptic Spatiotemporal Signals

“…3) The API values were parameterized, and re-mapped to a perceptually linear scale according to the Weber-Fechner law [12], using a literature sourced estimated just-noticeable-distance of 12% [9,13]). Following this calibration, pilot testing with 10 participants who performed a magnitude estimation and an intensity matching task confirmed that the adjusted left and right trigger motor outputs were perceived linearly and symmetrically in response to linear input commands.…”

Difference Thresholds for the Perception of Sinusoidal Vertical Stimuli of Whole-Body Vibrations in Ranges of Amplitude and Frequency Relevant to Ride Comfort

“…However, this series of studies did not confer to Weber's approach. Forta et al [15] investigated a frequency range between 2.5 Hz and 315 Hz at amplitude levels of 0.05 m/s 2 , 0.2 m/s 2 and 0.8 m/s 2 . The study used an electrodynamic shaker with a rigid seat made of wood as a test setup.…”

“…Moreover, previous studies mainly showed investigations on the surfaces of plates of electrodynamic shakers (Matsumoto et al [14]), rigid chairs (Bellmann et al [10][11][12]) or ergonomically shaped wooden surfaces (Forta et al [15]). In this way, test subjects assumed a posture clearly different from that in a vehicle.…”