Look for some of the electronic ear plugs. The cheap ones are at least a few hundred dollars, but it would allow you to still hear what is going on in the shop. I have not tried them for shooting, but auto work isn't as loud so even if they aren't enough for some shooters it may be good for auto work. In the garage, I use passive muffs rated at 30db. They are howard leight brand. For shooting, I use pro ears pro mag gold 31db electronic. They are huge, but the audio is good and they don't cut out during gun shots, they just reduce the volume of the shot while allowing you to hear people talking. The electronics do nothing to stop noise, but they allow you to hear what is going on. Some people think the electronic ears somehow are noise cancelling like headphones, but they are not.
My uncle is owns an auto shop and is once again a one man crew. Luckily his hearing doesn't seem too bad and he is getting close to retirement age. I'm 36 and years of construction work, stereos, races, etc. have taken a toll on my hearing. That is really bad if you already have hearing damage at 21.......it only gets worse.
At minimum, keep some $30 passive muffs on your tool cart. Don't go super cheap on them. The impacting is very loud and the hammering action transfers noise through the rest of the vehicle to make it louder. When I stopped by my uncle's shot the other day, he was working on a control arm of an suv and was whaling on a bolt or nut with his 3/8" IR. The sound transmitted through the spindle and other parts and bounced off the wheel well that was at eye level, on the lift.
When I used his lift the other day and did front end work on my truck, I used my muffs for the impact and air hammer with the pickle fork on it. Once your hearing gets jacked up, people may sing another tune. My hearing got more sensitive to loud sounds, yet I have a nice v notch high frequency hearing loss. And, that ringing, it started full time after an ear infection at age 17 and got worse 5 years ago with another infection. The second time made it bad enough that I can hear it over the tv with my left ear. Exposure to sound most likely started it, and the infection is the event that made it set it.
Ear plugs are great to keep **** out of your ears, especially if you do welding or plasma cutting. The other day, I had to replace the spring hanger on a trailer and it required laying under the trailer on my back and side while gouging out part of the bracket, grinding, and welding the new one in place. Hot metal down your ear canal really ***** and it can do some serious damage if it makes it all the way to the ear drum.
Stay safe.