Earplugs and band volume
"Conventional wisdom" holds that bands play louder at the end of a gig than at the beginning because of "higher energy", "more intensity", or a "rowdier audience". Conventional wisdom is mostly wrong.
Far too many musicians don't wear earplugs at gigs. Even though the stage is often quieter than the house, given venue-operators' tendencies to bludgeon the audience with dangerously-high SPLs in order to convince them that they're having a "quality" live-music experience, stage volumes are still a lot louder than can be sustained without hearing loss. So the musicians lose hearing sensitivity over the course of a show, and compensate by playing louder.
Of course, these same musicians will tell you that they don't wear earplugs in order to hear better. And then proceed to hear worse by the end of the show... If you're one of those musicians, try this at your next show. Use one earplug, leaving the other ear free to hear your pristine, unfiltered sound. The day after the show, see whether you notice that your open ear from the evening before seems a bit "dull" in comparison to your protected ear. If it does, you're suffering some hearing loss. If the exposure wasn't extreme, it'll seem to return to normal in a few days. Keep in mind though, that hearing damage is permanent and cumulative. Some of your ear's apparent "recovery" is just your brain adapting to the loss.
While you're at it, learn something about safe exposure levels. At the volumes most rock bands play, permanent hearing damage can occur in less than an hour. Beware of arguments that suggest that smaller amps are safe when compared to full- and half-stack 100W amps. The smaller amps tend to get pushed harder, mostly negating the benefits of any reduction in power. And even if you compared a dimed 100W amp vs. a dimed 20W amp, the safe exposure time only increases by a factor of two or three.
Unless your band actually does play at cocktail-lounge conversational level, get yourself some ear plugs. Musician's earplugs don't have to be custom-fitted, and they don't have to completely isolate you from the room the way that foam earplugs do.