Sentence:  Public relations strategists everywhere , watching the reaction of the German press , the liberal press , the lunatic fringe press , listening to their neighbors , studying interviews with men and women on the street , cried out : Too much , too much - the mind of the audience is becoming dulled , the horrors are <WSD>losing</WSD> their effect . 
Meaning of the word marked with <WSD> tags:  fail to keep or to maintain; cease to have, either physically or in an abstract sense