Answer:
That isn't always true. Some people, like myself, listen to music at a reasonable volume. Noise cancelling earbud helps us not have to turn music up so loud, so it saves hearing. For some people, sure this is right. But we need to think about the people who listen to loud music from stereos before earbuds. They still get to destroy their hearing, but lucky for us we don't have to hear their music from a block away.