Have you ever noticed that sounds that aren't loud during the day become disruptively loud sounds in the middle of the night? Just think about a text message coming in on your smartphone while you're driving, and there are a bunch of screaming kids in the backseat. You can barely hear that ding.
But, in the middle of the night, it can sound as loud as a fire engine alarm. It's loud, and it wakes you right up.
It's the same thing with your PC. Just think about all those dinging email alerts that you can barely hear half the time. But, when everything else around you is silent, they're really loud, although you haven't changed the volume.
That's the idea behind the free download Volume Concierge. It allows you to preset the volume on your PC for any time of day, and any day of the week.
It works this way. After download it, you can set up your whole week's volume levels. For example, you can start by having your PC's sound go all the way down to 20% of its max level every night at 10:00 p.m. You do that by selecting Every Day, then 10:00 p.m., then adjust the volume down to 20%.