i wish i had used earplugs when i was in middle school but i only started to use them in the 2nd year of high school. what stopped me? well if it had been found it'd be a nightmare. but actually i wish i had started doing that when i was in high school, when my parents supported me more. the problem is that they only reduce the teacher's voice but not to cancel it. so if my mind wasn't ready it might not make me feel better, then it wouldn't worth the risk of being caught. you need a lot of self-protection in your mind to make volume-reduce able to make you feel better.