This is Allie's husband - she found the 'high-fidelity' earplugs and got me a pair because she knew I'd been interested in better earplugs for quite a while. I have been a guitarist since I was 8. I played with a drummer for the first time when I was 12, and when my ears were still ringing into the night and the next morning, I remember thinking that I'd better be careful if I wanted to hear anything by the time I got old - like 30 (let's just say I'm not quite double that now). I began using foam earplugs pretty religiously at rehearsals, shows, and concerts, buying them in bulk and keeping an extra set or two in the car, guitar case, and gig bag so they'd always be around. I haven't had a real audiology exam since high school, but all these decades later, I notice that I seem to be able to hear better than many musician friends who blasted their ears out over the years. If you've used foam earplugs, you know that they attenuate (turn down) high frequencies (cymbals, sibilants, etc.) a lot more than low frequencies (bass, bass drums, etc.). It's always quite noticeable at first when I put them in that the lows come through louder than the highs, but the brain adapts after a bit and it's hardly noticeable, especially after using them for decades. I'd been interested in flatter-response earplugs for years, but I wasn't excited about the price (you can get like 500 foam earplugs for the price of one pair of these). My wife recently found out about these and got them in anticipation of the Chris Cornell tribute concert coming up next month (January, 2019), so I haven't had a chance to use them at an arena rock concert yet. But I am fortunate to have a 'premium' car audio system that sounds very good at low and high volumes, so I've spent a couple of days cranking it MUCH louder than what I usually call 'very loud' with these earplugs (when I'm able to drive around alone). The keychain container makes it easy to keep them handy. These aren't completely flat - see the chart from their website, which measures the standard audiology test range of 125Hz - 8kHz. Completely flat may be impossible, at least at a price point under something custom-made by an audiologist. However, the mids and highs are MUCH more present than with foam earplugs. My bet is that the curve for the foam earplugs I've been used to would continue steeply down after 2kHz. In other words, the Eargasm earplugs let much more of those mids and highs through, and whether it's simply that or some magic they put into the filter module, everything sounds much more clear (less muddy) than with the foam earplugs. I can turn the volume on my car stereo way past levels that would be uncomfortable without them, yet it's comfortably loud. And I can feel the bass that much more, which is fun. When I pull them out to see what it sounds like without them, it's just a LOT louder, so they go back in quickly. I do wish I didn't have close neighbors so I could listen at these levels at home... How much these 'turn it down' seems to depend on getting them adequately deep into your ear canal. The foam earplugs expand to fill the canal, so it took a few minutes to get used to these silicone tips. After they're in far enough that they feel fine, I've found that an extra nudge gets the tip to form a sort-of-vacuum-seal with the end of the ear canal. They don't fall out easily at this point, they're comfortable for at least two and a half hours straight so far, and I bet that the average attenuation indeed is at least the 21 dB they claim. Yes, they're worth the extra money. They're not disposable like the cheapo foamies, but the handy keychain case assuages my fear of losing them.