my .02 is that the muffs are ridiculous unless you're ACTUALLY dealing with mortars. Good molded earplugs with 15db filters, which come in clear and are discreet are well documented to drop sound 10+ decibels at 90db. Wearing higher filters will do even more. You're highly unlikely to damage your hearing with them in. Below 80db you're safe to be around sound for over eight hours. Unless you're going to a 3 day festival, you'll be fine.
This site is helpful but it's also a bastion of paranoia. Carry plugs with you. Always. They weigh nothing. Wear them when necessary. Nobody will notice. If they do - they don't give a shit. I have worn mine for months in loud bars, and even in a rehearsal studio with my guitar running through a 50W amp and a live drummer (measured at 95 db). I'm constantly exposed to sound living in one of the loudest places on Earth and being reliant on the train.
In this time my H symptoms have all but disappeared and my T has faded to 10% of what it was. Over protection won't make you worse - that's nonsense - but over protection WILL make you crazy.
see graphs below.
http://www.audiologyonline.com/articles/making-the-case-for-custom-12959
The whole 80db for 8 hours or TWA of sound exposure is based on very old data showing permanent threshold shifts seen on an audiogram. Suffice to say you can have a lot of hearing damage (hidden hearing loss) without it being reflected on a standard audiogram.