Can earplugs help me focus better?

Shutting out distracting aural stimuli in your vicinity can enhance your ability to concentrate.

Answer Extra: 

Using earplugs helps to keep your mind free from unwanted intrusions (or “white noise”), allowing you to keep your attention on what you’re doing, rather than what everyone else in the world is doing around you.

source: 
source: New York Times, 2009