I live on a cul-de-sac. My neighbor has a dog, in fact, many of my neighbors have dogs. Every now and then they will bark, which I'm pretty sure is a normal thing.
None of them are nuisances, as far as I'm concerned. There used to be one that barked for hours when the parents weren't home, and one guy who used to go on vacation and put his dog in the yard, and had someone drop off food and check on him. He would bark all night sometimes.
Other than that, normal dog barking.
So, about a year ago someone moved in to a property a couple of lots behind my neighbor. They both have large pie shaped lots at the end of their courts, and the homes are a considerable distance apart. Everyone on my court is closer to my neighbor than the new guy.
A couple of weeks after the new guy moved in, he sent my neighbor a letter introducing himself and saying he wanted to keep peace in the neighborhood, but he preferred it to be quiet from 7pm to 7am, and asked that he not allow his dogs to bark after 7pm or before 7am.
No one else in the neighborhood has complained about my neighbor's dogs, and we do occasionally hear other dogs barking. My neighbor wants to be a good one, but dogs do bark sometimes, and 7pm doesn't seem reasonable, and the dogs aren't particularly loud. One of them is 12 years old and nearly deaf, so he rarely barks at anything.
They sleep in the house, so aren't out barking late at night.
My neighbor has been more conscientious and aware, promised to keep the dogs quiet as much as possible, and if the dogs do bark he does bring them in or otherwise attempt to shut them up, but they are dogs and do have dog voices, and 7pm doesn't seem reasonable. I am 2 houses away, much closer than the other guy, and I haven't heard a peep out of them in weeks.
The complainer, on the other hand, has sent threatening emails, waited until after midnight once to call and wake him to 'let him know what it feels like', and now has filed a complaint with the city.