Effects of horizontal whole-body vibration on reading

Text from a newspaper was read by seated subjects (8 male, 8 female) during exposure to fore-and-aft and lateral whole-body vibration. With narrow-band random vibration at frequencies between 0.5 Hz and 10 Hz and with vibration magnitudes between 0.63 m s(-2) rms and 1.25 m s(-2) rms, reading speed was measured and subject ratings of reading speed were obtained. During exposure to fore-and-aft vibration, the subjects' ratings suggested that reading speed was significantly reduced at frequencies between 1.25 Hz and 6.3 Hz, with greater impairment at higher magnitudes of vibration. Maximum interference with reading was reported at 4 Hz. Measures of reading speed showed that subjects consistently overestimated their reduction in reading speed. Lateral vibration produced similar results, but the effect was less than that with fore-and-aft vibration.