EFFECTS OF 1-HZ AND 2-HZ TRANSIENT VERTICAL VIBRATION ON DISCOMFORT

The discomfort caused by 1-Hz and 2-Hz vertical sinusoidal vibration h as been studied with 20 seated subjects, using the method of magnitude estimation. The sinusoidal transients were superimposed on an 80-s ba ckground vibration which consisted of a 1-oct band of random vibration , centered on 1 Hz, with a magnitude of 0.63 m s(-2) rms. The transien ts were added at five magnitudes (0.63-1.6 m s(-2) rms) and seven dura tions (1-60 s). Male and female subjects produced comparable results a nd similar discomfort was produced by the two frequencies of vibration . Discomfort increased when the magnitudes or the durations of the tra nsients were increased. Of alternative methods of predicting the disco mfort, the overall vibration dose values gave the highest correlations with subject estimates, followed by the overall root-mean-square acce lerations. A lower correlation was found with peak acceleration and th e lowest correlation was with a running rms measurement, using a 1-s w indow. (C) 1995 Acoustical Society of America.