Being a smart and careful shooter today means that you use proper safety equipment. On the range this means ballistic eye protection and ear muffs/plugs. But what about in a real-life tactical situation?
Field ear protection
Adequate tactical ear protection that still allows ambient noise to reach the user while canceling out high decibel sound such as gunshots, has been used by the military for decades. Many operators attached to high-speed units such as Naval Special Warfare, US Army SF, and Marine Recon, are issued noise canceling Peltors or Sordins, and use them religiously. The groovy thing about these is that they cancel out up to 82db of sound while amplifying normal sounds, creating comic-book quality super-hearing. The bad thing about these is that they usually run $300 and higher
These are great for the range, survival prepping, and the occasional SHTF type of situation.
If the muffs are took much of a tactical option for you, there are more low-key systems that fit in the ear. These devices look more like conventional hearing aids and run a huge gamut in prices. Products like Remington's R-1700 Electronic Hearing Enhancement Ear Plugs can be had for as low as $25 and marketed towards the hunting and sport shooting market. While more discreet than earmuffs, they are still pretty noticeable.
While it certainly is possible to carry earplugs or even in-ear noise canceling inserts with you everywhere, it may not be probable to use them. What happens if you are confronted with a deadly threat and have to respond? You need to be able to react, draw, and fire a round in 2-3 seconds. If you can do that, you may be going home in a bag. That's not a lot of extra time to stop and insert your ear pro.
Home Defense Use
In reacting defensively to a threat inside your home, you may have more time to burn than when you are away from home. Unless the bad guy is already in your room, it is conceivable that you would have 4-10 seconds of warning to react. This could allow you sufficient time to put your enhanced Sordins on-- after you have armed yourself. However, keep in mind that if you plan for this, you need to train for this. Practice rising, safely arming, applying your ear pro, and moving to meet the threat. This needs to be done often and over the course of several days to develop a muscle memory for this task. If you are confident with it, then add your ear-pro to your kit and stage it with your firearm.
A Personal Tale
Myself, I use ear pro every time I'm on the range, which in my job is about 40-times a year. When hunting, unless it's with a suppressed weapon (if you ever have an extra $400, there is no better investment than a legal .22 suppressor), I always wear ambient noise amplifying ear pro. In EDC, plugs, muffs, and inserts are not a part of my kit. In a home defense scenario, while I have access to several types and sets, I personally am disinclined to use them.
My wife on the other hand, sleeps with earplugs every night I am home as she is a light sleeper. Another reason she wears then I also snore so loud I occasionally wake myself up. Still, she sleeps with a loaded P229 next to her side of the bed and qualifies DX with it quarterly with her agency. I asked her if she would keep her ear plugs in if she had to wake up to a threat.
"I might as well; it would help drown out your snores as I line up my sight picture."
Hey, that's why I love her.