Ear defender suggestions

Have recently noticed that 3M peltor optime 3 has been amplify not noise cancel and been having sensory overload daily from noisy area especially in crowds. I have fluacting senses with my autism can even hear on days with above human hearing from floor below alonfside with action causing that noise. Is anyone available to give suggestions since unable focus and concerned will effect class if suddenly able hear only sound or unable filter different conversations since not want seem rude or anti social since unable answer if stop hearing their words.