I do software programming, and I use the X5As in a shared office setting. The X5A is the best passive noise cancelling earmuff I've ever tried, and I've tested a lot of brands. They work well when used alone. In addition, if you use them with Bose active noise cancelling earbuds underneath, or with regular foam earplugs underneath, you will have a true impenetrable cone of silence. Voices don't get through at all, nor do any other sounds, low or high frequency. Compared with using Bose active noise cancelling over-the-ear headphones in an office setting, these X5As block more noise when used alone (that is, when used with no earbuds or earplugs underneath). When used with earplugs underneath, the two solutions are comparable in how much noise they block. That said, these 3Ms are cheap and the Bose cost multiple hundreds of dollars. I also love that these don't need batteries or charging. In that sense, they're super convenient. They're always ready to go and there are no wires to worry about. A similar advantage is that they're inexpensive, so I bring them while traveling and don't worry about them getting lost or broken. I once left these in a taxi and didn't worry about it like I would expensive noise-cancellers; I just bought a new pair. Outside of an office setting, I also like to reduce noise when I'm on airplanes. For airplanes, active noise cancelling headphones like Bose with foam earplugs underneath are the best option. That said, I've gone on airplanes with these 3M X5A earmuffs, and they are decent -- better than no ear protection at all especially pretty quiet with foam earplugs underneath, even if they don't do as well as active noise cancelling headphones for the low frequency airplane engine rumble. I liked the X5A so much that I also bought the X4A model of this product. I sleep in the X4A sometimes when I want very deep sleep, because they're low profile and comfortable enough to sleep in, and they can be used more nights in a row than heavy duty foam earplugs without ear irritiation. Sometimes I also wear the lighter X4A model around my city apartment because they're not as heavy and bulky as the X5As but still do a pretty great job of noise blocking. Not as impenetrable as the X5A but still really good. All in all, this 3M earmuffs series is absolutely top of the line. I've ordered many of the cheaper and knock-off brands here on Amazon to compare them because I wanted the best product for use in my office and around my city apartment. I'm someone who concentrates better and is more productive when I don't have noise distractions. Hands down, the X5As are the best passive noise blockers of any earmuffs on the market, and the X4As are the best low profile and smaller noise blockers. There are a ton of knock off brands for passive earmuffs, usually made in China by a few relatively less known companies. Some examples are Clear Armour and DD. Those knock off brands are okay but in my opinion, they do not compare with the 3Ms which are the "OG" passive earmuffs. You can order them side-by-side to compare -- they're not too expensive -- but I already did that comparison so you don't have to and you can take the results of my research if you want. The only downside I will mention here is that any earmuffs -- 3M brand or others -- can make your ears sweat if you sleep in them or wear them for multi-hour stretches at work. I think that's inevitable with any earmuffs in this style because they work in part by creating a seal around your ears. It's not a vice-like seal; it's pretty gentle but a seal nonetheless. The way I handle the sweat issue for everyday office use is to switch the earmuffs occasionally with less sweaty noise cancelling options like the Bose noise cancelling earbuds, foam earplugs, or the Bose active noise cancelling over-the-ear headphones which make less of a tight seal because they don't have to. Because you do sweat in these, after extended use they will begin to get a little bit of an odor. The good news is that you can replace the foam padding, and as far as I know, these are the only comparable earmuffs that let you do that. Cleaning with a warm towel and some scented product also works pretty well. Lastly, you can tell by the photos that X5As look outrageously ridiculous. If the photos here are not enough, Google Bose X5A to see some more. These are not earmuffs to take selfies in. They are earmuffs when you have a good reason to wear them. For me, that reason is maximum productivity in my shared office, where a lot of people wear noise blockers of various types. All in all, I'm a huge fan of the X5As and X4As! Very glad they exist. These are a nicely engineered product.