My neighbor's dog is left outside 24/7/365. Approximately 1/3 of its waking hours are dedicated solely to barking. Sirens trigger barking, other dogs barking triggers barking, me opening my door two houses down triggers barking, and being a bored dog triggers barking. The front of my house is brick and does well against its aural assault, but my back section just has some vinyl siding and thin layers of fiberglass insulation and drywall to ward off its attack.
I've realized that by me reacting negatively to the barking noises, it's as if I'm another dog and I'm responding with my own internal barking and sometimes verbal cursing. It's a dog and it's poorly trained. I can't do anything about it (notes and threats did no good and I'm not about to call the cops) so I just need to accept it, let it go and let the sounds pass right through me. The barking is there, but I refuse to focus on it and react negatively. The only exception where the noise if I'm trying to take a nap on my deck, the combo of earplugs and earmuffs is usually enough to make my breathing the dominant noise. It feels great to having this empowering attitude and not feel like a hostage in my own home. Ignoring is bliss.