Moved to the lounge, 'cause... yeah.
You live near a construction site, go to shooting ranges a lot, etc.? Or do ya listen to your music with the volume jacked up (you might not think it as loud; but if say other people can hear it clearly through headphones/buds, then that 100% qualifies as way too loud)? If you can turn down the volume on anything, do it whenever possible. Otherwise ya will start killing your hearing permanently. Ringing for a few hours straight is definitely not somethin' normal. Certainly ain't a doctor, but I know that much.
... Certain sickness can cause your ears to ring as well, I hear. In these cases that's probably got somethin' to do with your sinuses, I reckon. Likewise, ear infections can cause severe ringin' like that too.