It would be nice if we could simply rely on people being courteous and using their common sense, but that often doesn't work out. Many people simply do what they want without any regard for their neighbors. Having a noise ordinance ensures that everyone can have peace and quiet to sleep, or just enjoy their homes and yards.
Noise ordinances are important for ensuring that people residing in the jurisdiction are able to get the night's sleep they require to be productive in the workplace, and thus increase their overall economic output. It is also a matter of convenience, one shouldn't feel hostage in their own home, unable to escape the loud noises caused by others.
I think there needs to be a regulation on the amount of noise a company or individual can commit, people producing excessive amounts of noise greatly disrupt those around them and I think to be fair and considerate noise ordinances need to set the maximum level of noise that can be produced.
No, noise ordinances are not necessary in all jurisdictions. The decision whether or not to make loud noises, particularly in a residential area, should remain a matter of common sense. There are enough laws that take on the role of a "nanny" in society, keeping people from harming themselves. Noise ordinances are just another example of this trend.
We should not simply go down to something like this it should be up to the people who are in the communities themselves to decide not other people. Communities know what they need in order to make things operate in their cities. Some jurisdictions may need them where others do not.