Without my proper earplugs I have been using Elacin ER20s and ProGuard PR20s, both of which seem pretty good although the ProGuards are more comfortable for longer periods of time. The-off-the-shelf musician’s earplugs are not bad, I think all musicians should have a pair and use them regularly when practicing, gigging or when listening to live music, but for the amount of time I have my ears plugged, they don’t really cut it. The comfort offered by custom moulded earplugs is incomparable and I believe the protection for my ears is better. After using the off-the-shelf plugs, my ears still feel fatigued.
If you are a busy musician or teacher exposed to loud music for hours at a time, I strongly recommend you invest in a pair of custom earplugs.
I’d like to give a plug (geddit?) to Gisele the audiologist at Aid2Hearing who took the impressions for the earplugs and got them made for me, she offered a great service and is highly recommended to anyone in the London area.