Decibels are a logarithmic ratio between two quantities, and a good method to describe sound intensity. There are loud sounds that could annoy neighbors and the possibility of experiencing legal issues because the existence of regulations in this regard.
Very common appliances like vacuum cleaners reach considerable noise levels, up to 90dB or more. Do it yourself electrical hand tools also could surpass 90dB with ease, specially drills or grinders, air compressors, ... Manufacturers usually "forget" clear specifications or mislead using false statements like "optimized motor for low noise" without providing numbers at first glance. If that happens, it's a bad signal and perhaps to search for another option would be better for avoiding problems.
Human shouting records put the bar in about 130dB, so it's another number to remember. Commonly lower than 110dB but close.
Drums, percussion, instruments with amplification...
If some sources at home reach 90dB or more, and multiple local regulations establish even near 30dB at maximum, simply using them could be enough for being in a court giving explanations. This is a matter of how tolerant your neighbors are. In case that they are not, the availability of tools that measure sound pressure in an accurate form, and video recording it would be enough for demonstrating those actions against the law. Not recommendable!