Selective hearing is about to go from being a figure of speech to a new reality. Smart Earplug offers the option of controlling sound that’s being blocked. Through the use of a built-in sliding window, users can gradually decrease or increase the sound that is impacting their eardrums. Whether it’s a noisy work environment, a rock concert, air travel or parents seeking peace and quiet from noisy kids, volume controlled earplugs let users decide how loud is too loud. For $18, backers can get the early bird special of one pair with an expected delivery of August 2014.