Normally, human ears are incredibly good at focusing on sounds of specific frequencies and simultaneously filtering out the rest of the noise — your drinking buddy’s voice in a crowded bar, for example. This is why you can have conversations in places with a wild and crazy soundscape. If we paid attention to all the noises all the time, there would be no way to distinguish between your friend’s on-the-spot beer review and the clamor of vapid background conversations.
As we age, though, this ability to focus on particular frequencies wanes. Which is why, if you’re like me and enjoy hanging out with your parents in bars, you find yourself yelling more loudly as the years go on.