Most buildings require residents to soundproof their apartments at least 80 percent, covering floors with rugs or carpets, ensuring better soundproofing. However, sometimes noise may still penetrate walls. It is always better to check for small holes because even if you may have additional soundproofing applied to your apartment, one small hole will render the effort futile. Ensure your neighbors have soundproofing as well. Many of the condos can be pretty specific or vague with what they term as noise nuisances in condos, so it is time you find out what your condo rules are regarding noise. You can talk to your neighbor regarding the noise they are creating or file a complaint to the condo board against them. Some condos place a fine or send out formal warnings to residents who violate the rules.