The effect on speech intelligibility was measured for speech where talkers reading Diagnostic Rhyme Test material were exposed to 0.7 g whole body vibration to simulate space vehicle launch . Across all talkers , the effect of vibration was to degrade the percentage of correctly transcribed words from 83 % to 74 % . The magnitude of the effect of vibration on speech communication varies between individuals , for both talkers and listeners . A worst case scenario for intelligibility would be the most sensitive listener hearing the most sensitive talker ; one participant s intelligibility was reduced by 26 % ( 97 % to 71 % ) for one of the talkers .