Noise is unwanted or meaningless sound that disrupts, distracts, or annoys. When your little brother bangs on pots and pans while you're trying to read, that's noise. When static crackles through a radio and makes it hard to hear the music, that's noise too.

The key thing about noise is that it interferes with something you're trying to do or hear. The same sound might be noise in one situation but not in another. Rain pattering on the roof could be peaceful background sound when you're cozy inside, but noise when you're trying to hear your teacher during an outdoor lesson.

Scientists and engineers use noise to describe any unwanted interference in a signal or system. A grainy photograph has visual noise. A weak phone connection has noise that makes voices sound fuzzy or distorted. When researchers try to find a pattern in their data, they have to separate the real information from the random noise.

People also use noise to mean meaningless chatter or fuss about nothing important. If someone says “ignore the noise,” they mean don't pay attention to all the distracting complaints or rumors swirling around. They're telling you to focus on what actually matters and tune everything else out.