why not use "pro" moulded (personalized to your ears and to your hearing) earplugs with changeable filter?
Exactly - you'll never make these things quiet, so best to simply stop the noisy making you grumpy. I have a set of ACS Encore Studio Custom in-ear Monitors and their sound quality is quite extraordinary. Plus they cancel out all the external noise when I don't need to have music (or satnav instructions) running in the background.
