One of the biggest complaints among apartment renters is being able to hear the sound from the people you share your walls with. Many apartments don't have the proper sound proofing systems in place, like soundproof sheet rock, to keep the noise from traveling from one apartment to the next.
But you're not out of luck if your apartment doesn't have good soundproofing; you just need to get creative. You can hang sound-absorbent panels on your walls to catch some of the sound coming from your neighbor. Products like corkboards can be wrapped in fabric and hung on the walls to absorb sound. Many online retailers sell special sound-absorbent panels you can order as well. These panels will help dampen the sound coming from your apartment, but they'll also help absorb sound coming from the walks they're placed on as well. Not only will these panels help cancel some of the sound, you can use them to decorate your walls as well. Plus, it'll make your apartment conversations a little more private as well.
If you happen to own the condo or space you're living in, you can always add an extra layer of sheetrock on top of your existing wall to really dampen the sound. There are even sound-absorbent products, like Homasote, made specifically for that purpose.