Loop headphones and Dogs Barking

My fiancé has misophonia and one of his biggest triggers are dogs barking. He cannot spend much time outside at our house because of the neighbors dogs constantly barking. It really frustrates him that he can't be outside more so I wanted to get him some Loop earplugs to try (or something similar). The problem is, the dogs are far away. We live on 5 acres and we think the dogs are on a property whose fence line is about 1,000ft away from our fence line. You can always hear the dog clear as day but it's not necessarily loud. Would loop earplugs even work? Or is there something else he could try?

Edit: change headphones to earplugs