I want something a bit more selective. Like, capable of completely blocking out the sound of my wife snoring.

I’m sure that I’m not the only one in this boat, but I may be one of the rare males complaining about their wife snoring.

That sounds like a really interesting problem. You'd need microphones good enough, small enough, and cheap enough to hear the signal, Signals processing/machine learning software robust enough to pick up a user-selected pattern and in a reasonable latency, and then a processor small enough and power efficient enough to process it all while again also being economical enough, and then have it last 8 hours.

"Completely blocking out" is out of reach, technologically; you'd need 80+ dB of attenuation, and the best anyone can do with things that fit around your head (earplugs, noise-canceling, etc.) is about 40, before you even start to touch the questions of selectivity and power usage. If you need 80 dB of attenuation your best bet is to contract an acoustics engineer to build a wall out of several layers of different materials.

Part of snoring is low frequency sounds, which even with fully plugged ears, transmits through bone conduction.

also long term use of ear plugs with sleeping can cause unwanted side-effects.

When we sleep our hearing system does not turn off (safety), and when you wear ear plugs while sleeping you run the risk of making your hearing work harder - and then if you have no plugs in your hearing system is now (hopefully temporarily) more sensitive than before.

one upside of being hearing impaired: the wifes snoring doesn't bother me much.

Huh, looks like they also have these for music: https://www.etymotic.com/product/music-pro/

Has anyone here tried them? I'm very curious how well they'd work to use at concerts.

They are excellent compared to standard ear-plugs.

Not as much reduction in harmful sounds (do not use with heavy equipment for example) but do a great job of equally attenuating a wide freq band.

I use their passive ER20SX ear plugs for concerts and love them. The active hearing protection they make look great but rather expensive.

I've got a product similar to these and they're great. You can have a normal conversation and it didn't take me long to realize their eavesdropping potential. My Surface headphones also have a feature that more or less acts as a hearing aid.

Some years ago there was a set of headphones sold for hunting (amplifying sounds of animals and reducing gunshot noise) that were very popular among the hearing-impaired community as a cheaper alternative to hearing aids.

If all you need is to amplify everything, they work fine.