Hearing issues yes, but also...

it was loud, you couldn't see much, you'd crouch most of the time and move tons of cannons around. If you were unlucky this was going on for hours. If you gun crew was any good, you would fire 2 or 3 shots every 3 minutes while the balls of the enemy ripped the hull around you.

You'd see a 9 year old boy next to you get torn to pieces by flying wood splinters the lenght of your arm, it reeked of blood and piss and sweat.

As this was going on with every shot the cannon was getting hotter and hotter, maybe you burn your skin on the powder hole or the lint or the muzzle while swabbing. The hotter the cannon got, the more unpredictable it became on the bounce back, the ropes holding it began to wear down or the iron fittings broke and loose guns might be rolling over the deck, transforming into a multiple ton bullet.