Thanks for the thorough rundown, Tom.
The ACS and ER filters look different (link below), do you mean that they're interchangeable whatever brand I go with, or just that they will be of the same quality?
https://www.pacificears.co.nz/product/pro-filters/
https://www.pacificears.co.nz/product/er-filters/
Your explanation of the different dB filters, the full cap and difference between them and the foam earplugs is most appreciated as well!
I actually went to a bar on Friday night (first time for about a month). I've never used a dB meter so I'm not a good judge of how loud it actually was, but I avoided all of the booming louder bars and wore Alpine MusicSafe Pro earplugs rated 18.5-22.9 NRR the entire time, which judging by what other people have said should have been more than sufficient. I also spent a lot of the evening outside. When I got home I noticed immediately the ringing was louder and this continued throughout Saturday and Sunday and isn't quite back to where it was even now, but appears to have settled down a bit. Needless to say it freaked me out a lot and is making me think I'm not quite ready for bars yet. Although, it's entirely possible I also made a stupid mistake like misjudging the dB level, bass level, fitting the earplugs incorrectly etc. (although they're pretty easy ones to fit and the videos/tutorials I've watched appear to be exactly how I did it), but I don't really have much prior experience to know if I misjudged anything. I'm planning on getting a dB meter to check for the future, so I can gauge how loud a place is. I've got one on my phone, but not sure of its accuracy.
Hopefully my reaction to those places will settle down over time, but I think I'll probably stick with the strongest ones for now if I find myself in a louder environment, just for peace of mind and to be on the safe side.
Thanks again for the help!