You don't know whether they are having fun: they may as well be fighting a lot. But let's assume they are having fun: people can have fun without making a lot of noise.
In fact, the question is why people make a lot of noise in the first place. It doesn't seem like a very good evolutionary strategy, which suggests it is in fact learned behavior with a cultural source. In which case it may not be a bad idea to try and unlearn your children this behavior.
It is advantageous for kids to make their location known to adults who protect them from danger. Why adults make noise,I don't know. Usually juvenile, drunk adults are noisier.
In fact, the question is why people make a lot of noise in the first place. It doesn't seem like a very good evolutionary strategy, which suggests it is in fact learned behavior with a cultural source. In which case it may not be a bad idea to try and unlearn your children this behavior.