As a counterproduct, I recently discovered noise-cancelling earplugs for musicians. They work like headphones except that they don't generate sound, only reduce some frequencies. Great for people with sensitive hearing.
I can second that, love mine. No more tinnitus-like noises from fatigued ears after concerts or the cinema. And they even help with acoustics somewhat when they arent ideal at the venue, like at festivals or Nolan movies ;)